21
Answers Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. Chapter 3 A1 Glencoe Algebra 1 Lesson 3-1 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. NAME DATE PERIOD Chapter 3 5 Glencoe Algebra 1 Identify Linear Equations and Intercepts A linear equation is an equation that can be written in the form Ax + By = C. This is called the standard form of a linear equation. Determine whether y = 6 - 3x is a linear equation. Write the equation in standard form. First rewrite the equation so both variables are on the same side of the equation. y = 6 - 3x Original equation. y + 3x = 6 - 3x + 3x Add 3x to each side. 3x + y = 6 Simplify. The equation is now in standard form, with A = 3, B = 1 and C = 6. This is a linear equation. Determine whether 3xy + y = 4 + 2x is a linear equation. Write the equation in standard form. Since the term 3xy has two variables, the equation cannot be written in the form Ax + By = C. Therefore, this is not a linear equation. Exercises Determine whether each equation is a linear equation. Write yes or no. If yes, write the equation in standard form. 1. 2x = 4y 2. 6 + y = 8 3. 4x - 2y = -1 4. 3xy + 8 = 4y 5. 3x - 4 = 12 6. y = x 2 + 7 7. y - 4x = 9 8. x + 8 = 0 9. -2x + 3 = 4y 10. 2 + 1 2 x = y 11. 1 4 y = 12 - 4x 12. 3xy - y = 8 13. 6x + 4y - 3 = 0 14. yx - 2 = 8 15. 6x - 2y = 8 + y 16. 1 4 x - 12y = 1 17. 3 + x + x 2 = 0 18. x 2 = 2xy Study Guide and Intervention Graphing Linear Equations 3-1 Standard Form of a Linear Equation Ax + By = C, where A 0, A and B are not both zero, and A, B, and C are integers with GCF of 1. Example 1 Example 2 yes; 2x - 4y = 0 yes; y = 2 yes; 4x - 2y = -1 no yes; 3x = 16 no yes; 4x - y = -9 yes; x = -8 yes; 2x + 4y = 3 yes; x - 2y = -4 yes; 16x + y = 48 no yes; 6x + 4y = 3 no yes; 6x - 3y = 8 yes; x - 48y = 4 no no Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. NAME DATE PERIOD Chapter Resources Chapter 3 3 Glencoe Algebra 1 Before you begin Chapter 3 • Read each statement. • Decide whether you Agree (A) or Disagree (D) with the statement. Write A or D in the first column OR if you are not sure whether you agree or disagree, write NS (Not Sure). STEP 1 A, D, or NS Statement STEP 2 A or D 1. The equation 6x + 2xy = 5 is a linear equation because each variable is to the first power. 2. The graph of y = 0 has more than one x-intercept. 3. The zero of a function is located at the y-intercept of the function. 4. All horizontal lines have an undefined slope. 5. The slope of a line can be found from any two points on the line. 6. A direct variation, y = kx, will always pass through the origin. 7. In a direct variation y = kx, if k < 0 then its graph will slope upward from left to right. 8. A sequence is arithmetic if the difference between all consecutive terms is the same. 9. Each number in a sequence is called a factor of that sequence. 10. Making a conclusion based on a pattern of examples is called inductive reasoning. After you complete Chapter 3 Reread each statement and complete the last column by entering an A or a D. • Did any of your opinions about the statements change from the first column? For those statements that you mark with a D, use a piece of paper to write an example of why you disagree. 3 Anticipation Guide Graphing Relations and Functions Step 1 Step 2 D A D D A A D A D A Answers (Anticipation Guide and Lesson 3-1)

Answers (Anticipation Guide and Lesson 3-1) · Identify Linear Equations and Intercepts A linear equation is an equation that can be written in the form Ax + ... Anticipation Guide

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Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A1 Glencoe Algebra 1

Lesson 3-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

5

Gle

ncoe A

lgeb

ra 1

Iden

tify

Lin

ear

Eq

uati

on

s an

d I

nte

rcep

ts

A l

inea

r e

qu

ati

on

is

an

equ

ati

on

th

at

can

be w

ritt

en

in

th

e f

orm

Ax

+ B

y =

C.

Th

is i

s ca

lled

th

e s

tan

da

rd

fo

rm

of

a l

inear

equ

ati

on

.

D

ete

rm

ine w

heth

er y

= 6

- 3

x

is a

lin

ea

r e

qu

ati

on

. W

rit

e t

he e

qu

ati

on

in

sta

nd

ard

fo

rm

.

Fir

st r

ew

rite

th

e e

qu

ati

on

so b

oth

vari

able

s are

on

th

e s

am

e s

ide o

f th

e e

qu

ati

on

.

y =

6 -

3x

Origin

al equation.

y +

3x =

6 -

3x +

3x

Add 3

x t

o e

ach s

ide.

3

x +

y =

6

Sim

plif

y.

Th

e e

qu

ati

on

is

now

in

sta

nd

ard

form

, w

ith

A =

3,

B =

1 a

nd

C =

6.

Th

is i

s a l

inear

equ

ati

on

.

D

ete

rm

ine

wh

eth

er 3

xy +

y =

4 +

2x i

s a

lin

ea

r e

qu

ati

on

. W

rit

e t

he

eq

ua

tio

n i

n s

tan

da

rd

fo

rm

.

Sin

ce t

he t

erm

3xy h

as

two v

ari

able

s,

the e

qu

ati

on

can

not

be w

ritt

en

in

th

e

form

Ax +

By =

C.

Th

ere

fore

, th

is i

s n

ot

a l

inear

equ

ati

on

.

Exerc

ises

Dete

rm

ine w

heth

er e

ach

eq

ua

tio

n i

s a

lin

ea

r e

qu

ati

on

. W

rit

e y

es o

r n

o.

If y

es,

writ

e t

he e

qu

ati

on

in

sta

nd

ard

fo

rm

.

1. 2

x =

4y

2. 6 +

y =

8

3. 4

x -

2y =

-1

4. 3

xy

+ 8

= 4

y

5. 3x

- 4

= 1

2

6. y

= x

2 +

7

7. y

- 4

x =

9

8. x

+ 8

= 0

9.

-2x

+ 3

= 4

y

10. 2

+ 1

2 x

= y

11. 1

4 y

= 1

2 -

4x

12. 3

xy

- y

= 8

13. 6x

+ 4

y -

3 =

0

14. yx

- 2

= 8

15. 6

x -

2y

= 8

+ y

16. 1

4 x

- 1

2y

= 1

17. 3

+ x

+ x

2 =

0

18. x

2 =

2xy

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Gra

ph

ing

Lin

ear

Eq

uati

on

s

3-1

Sta

nd

ard

Fo

rm o

f a L

inear

Eq

uati

on

Ax +

By

= C

, w

here

A ≥

0,

A a

nd B

are

not

both

zero

, and A

, B

, and

C a

re inte

gers

with G

CF

of

1.

Exam

ple

1Exam

ple

2

y

es;

2x

- 4

y =

0

yes;

y =

2

yes;

4x

- 2

y =

-1

n

o

yes;

3x

= 1

6

no

y

es;

4x

- y

= -

9

yes;

x =

-8

yes;

2x

+ 4

y =

3

y

es;

x -

2y

= -

4

yes;

16x

+ y

= 4

8

no

y

es;

6x

+ 4

y =

3

no

y

es;

6x

- 3

y =

8

y

es;

x -

48

y =

4

no

n

o

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Chapter Resources

Ch

ap

ter

3

3

Gle

ncoe A

lgeb

ra 1

B

efo

re y

ou

beg

in C

ha

pte

r 3

R

ead

each

sta

tem

en

t.

D

eci

de w

heth

er

you

Agre

e (

A)

or

Dis

agre

e (

D)

wit

h t

he s

tate

men

t.

W

rite

A o

r D

in

th

e f

irst

colu

mn

OR

if

you

are

not

sure

wh

eth

er

you

agre

e o

r d

isagre

e,

wri

te N

S (

Not

Su

re).

ST

EP

1A

, D

, o

r N

SS

tate

men

tS

TE

P 2

A o

r D

1.

Th

e e

qu

ati

on

6x +

2xy =

5 i

s a l

inear

equ

ati

on

beca

use

each

vari

able

is

to t

he f

irst

pow

er.

2.

Th

e g

rap

h o

f y =

0 h

as

more

th

an

on

e x

-in

terc

ep

t.

3.

Th

e z

ero

of

a f

un

ctio

n i

s lo

cate

d a

t th

e y

-in

terc

ep

t of

the

fun

ctio

n.

4.

All

hori

zon

tal

lin

es

have a

n u

nd

efi

ned

slo

pe.

5.

Th

e s

lop

e o

f a l

ine c

an

be f

ou

nd

fro

m a

ny t

wo p

oin

ts o

n t

he

lin

e.

6.

A d

irect

vari

ati

on

, y =

kx,

wil

l alw

ays

pass

th

rou

gh

th

e o

rigin

.

7.

In a

dir

ect

vari

ati

on

y =

kx,

if k

< 0

th

en

its

gra

ph

wil

l sl

op

e

up

ward

fro

m l

eft

to r

igh

t.

8.

A s

equ

en

ce i

s ari

thm

eti

c if

th

e d

iffe

ren

ce b

etw

een

all

co

nse

cuti

ve t

erm

s is

th

e s

am

e.

9.

Each

nu

mber

in a

sequ

en

ce i

s ca

lled

a f

act

or

of

that

sequ

en

ce.

10.

Mak

ing a

con

clu

sion

base

d o

n a

patt

ern

of

exam

ple

s is

call

ed

in

du

ctiv

e r

easo

nin

g.

A

fter y

ou

com

ple

te C

ha

pte

r 3

R

ere

ad

each

sta

tem

en

t an

d c

om

ple

te t

he l

ast

colu

mn

by e

nte

rin

g a

n A

or

a D

.

D

id a

ny o

f you

r op

inio

ns

abou

t th

e s

tate

men

ts c

han

ge f

rom

th

e f

irst

colu

mn

?

F

or

those

sta

tem

en

ts t

hat

you

mark

wit

h a

D,

use

a p

iece

of

pap

er

to w

rite

an

exam

ple

of

wh

y y

ou

dis

agre

e.

3A

nti

cip

ati

on

Gu

ide

Gra

ph

ing

Rela

tio

ns a

nd

Fu

ncti

on

s

Ste

p 1

Ste

p 2

D A D D A A D A D A

Answers (Anticipation Guide and Lesson 3-1)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A2 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

6

Gle

ncoe A

lgeb

ra 1

Gra

ph

Lin

ear

Eq

uati

on

s T

he g

rap

h o

f a l

inear

equ

ati

on

s re

pre

sen

ts a

ll t

he s

olu

tion

s of

the e

qu

ati

on

. A

n x

-coord

inate

of

the p

oin

t at

wh

ich

a g

rap

h o

f an

equ

ati

on

cro

sses

the x

-axis

in

an

x-i

nte

rcep

t. A

y-c

oord

inate

of

the p

oin

t at

wh

ich

a g

rap

h c

ross

es

the y

-axis

is

call

ed

a

y-i

nte

rcep

t.

G

ra

ph

th

e

eq

ua

tio

n 3x

+ 2y

= 6

by

usin

g t

he

x a

nd

y-i

nte

rcep

ts.

To f

ind

th

e x

-in

terc

ep

t, l

et

y =

0 a

nd

so

lve f

or

x.

Th

e x

-in

terc

ep

t is

2.

Th

e

gra

ph

in

ters

ect

s th

e x

-axis

at

(2,

0).

To f

ind

th

e y

-in

terc

ep

t, l

et

x =

0 a

nd

so

lve f

or

y.

Th

e y

-in

terc

ep

t is

3.

Th

e g

rap

h

inte

rsect

s th

e y

-axis

at

(0,

3).

Plo

t th

e p

oin

ts (

2,

0)

an

d (

0,

3)

an

d

dra

w t

he l

ine t

hro

ugh

th

em

.

Exerc

ises

Gra

ph

ea

ch

eq

ua

tio

n b

y u

sin

g t

he x

- a

nd

y-i

nte

rcep

ts.

1. 2

x +

y =

-2

2. 3x

- 6

y =

-3

3.

-2x

+ y

= -

2

x

y

Ox

y Ox

y O

Gra

ph

ea

ch

eq

ua

tio

n b

y m

ak

ing

a t

ab

le.

4. y

= 2

x

5. x

- y

= -

1

6. x

+ 2

y =

4

x

y

Ox

y

Ox

y O

x

y O

G

ra

ph

th

e e

qu

ati

on

y -

2x

= 1

by

ma

kin

g a

ta

ble

.

Solv

e t

he e

qu

ati

on

for

y.

y

- 2

x =

1

Origin

al equation.

y -

2x

+ 2

x =

1 +

2x

Add 2

x t

o e

ach s

ide.

y

= 2

x +

1

Sim

plif

y.

Sele

ct f

ive v

alu

es

for

the d

om

ain

an

d m

ak

e a

table

. T

hen

gra

ph

th

e o

rdere

d p

air

s an

d d

raw

a l

ine

thro

ugh

th

e p

oin

ts.

y

xO

( 2,

0)

( 0,

3)

3-1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n (c

on

tin

ued

)

Gra

ph

ing

Lin

ear

Eq

uati

on

s

x2x

+ 1

y(x

, y)

-2

2(-

2)

+ 1

-3

(-2,

-3)

-1

2(-

1)

+ 1

-1

(-1,

-1)

0

2(0

) +

1

1(0

, 1)

1

2(1

) +

1

3(1

, 3)

2

2(2

) +

1 5

(2,

5)

Exam

ple

1Exam

ple

2

Lesson 3-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

7

Gle

ncoe A

lgeb

ra 1

Dete

rm

ine w

heth

er e

ach

eq

ua

tio

n i

s a

lin

ea

r e

qu

ati

on

. W

rit

e yes o

r no.

If y

es,

writ

e t

he e

qu

ati

on

in

sta

nd

ard

fo

rm

.

1. xy

= 6

2. y

= 2

- 3

x

3. 5

x =

y -

4

4. y

= 2

x +

5

5. y

= -

7 +

6x

6. y

= 3

x2 +

1

7. y

- 4

= 0

8. 5x

+ 6

y =

3x

+ 2

9. 1

2 y

= 1

Fin

d t

he x

- a

nd

y-i

nte

rcep

ts o

f ea

ch

lin

ea

r f

un

cti

on

.

10.

11.

12.

Gra

ph

ea

ch

eq

ua

tio

n b

y m

ak

ing

a t

ab

le.

13. y

= 4

14. y

= 3

x

15. y

= x

+ 4

Gra

ph

ea

ch

eq

ua

tio

n b

y u

sin

g t

he x

- a

nd

y-i

nte

rcep

ts.

16. x

- y

= 3

17. 10x

= -

5y

18. 4

x =

2y

+ 6

x

y

O

x

y

Ox

y

O

x

y

Ox

y

Ox

y

O

x

y

Ox

y

Ox

y

O

3-1

Sk

ills

Pra

ctic

e

Gra

ph

ing

Lin

ear

Eq

uati

on

s

n

o

yes;

3x

+ y

= 2

y

es;

5x

- y

= -

4

y

es;

2x

- y

= -

5

yes;

6x

- y

= 7

n

o

y

es;

y =

4

yes;

x +

3y

= 1

y

es;

y =

2

x

-in

terc

ep

t: 2

,

x-i

nte

rcep

t: 4

, x

-in

terc

ep

t: 2

,

y-i

nte

rcep

t: -

2

y-i

nte

rcep

t: 4

y

-in

terc

ep

t: 4

Answers (Lesson 3-1)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A3 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

8

Gle

ncoe A

lgeb

ra 1

Dete

rm

ine w

heth

er e

ach

eq

ua

tio

n i

s a

lin

ea

r e

qu

ati

on

. W

rit

e yes o

r no.

If y

es,

writ

e t

he e

qu

ati

on

in

sta

nd

ard

fo

rm

an

d d

ete

rm

ine t

he x-

an

d y-i

nte

rcep

ts.

1. 4xy

+ 2

y =

9

2. 8x

- 3

y =

6 -

4x

3. 7

x +

y +

3 =

y

4. 5

- 2

y =

3x

5.

x

4 -

y

3 =

1

6. 5

x -

2

y =

7

Gra

ph

ea

ch

eq

ua

tio

n.

7. 1

2 x

- y

= 2

8. 5x

- 2

y =

7

9. 1.5

x +

3y

= 9

10. C

OM

MU

NIC

AT

ION

S A

tel

eph

one

com

pan

y c

harg

es

$4.9

5 p

er m

onth

for

lon

g d

ista

nce

call

s p

lus

$0.0

5 p

er

min

ute

. T

he

mon

thly

cos

t c

of l

ong d

ista

nce

call

s ca

n b

e d

escr

ibed

by t

he

equ

ati

on c

= 0

.05

m +

4.9

5,

wh

ere

m i

s th

e n

um

ber

of

min

ute

s.

a.

Fin

d t

he

y-i

nte

rcep

t of

th

e gra

ph

of

the

equ

ati

on.

b.

Gra

ph

th

e eq

uati

on.

c.

If y

ou t

alk

140 m

inu

tes,

wh

at

is t

he

mon

thly

cos

t?

11. M

AR

INE

BIO

LO

GY

K

ille

r w

hale

s u

suall

y s

wim

at

a

rate

of

3.2

–9.7

kil

omet

ers

per

hou

r, t

hou

gh

th

ey c

an

tra

vel

u

p t

o 48.4

kil

omet

ers

per

hou

r. S

up

pos

e a m

igra

tin

g k

ille

r w

hale

is

swim

min

g a

t an

aver

age

rate

of

4.5

kil

omet

ers

per

h

our.

Th

e d

ista

nce

d t

he

wh

ale

has

travel

ed i

n t

hou

rs c

an

be

pre

dic

ted

by t

he

equ

ati

on d

= 4

.5t.

a.

Gra

ph

th

e eq

uati

on.

b.

Use

th

e gra

ph

to

pre

dic

t th

e ti

me

it t

ak

es t

he

kil

ler

wh

ale

to

travel

30 k

ilom

eter

s.

Tim

e (

ho

urs

)

Kil

ler

Wh

ale

Tra

vels

Distance (km)

02

46

89

13

57

40

35

30

25

20

15

10 5

Tim

e (

min

ute

s)

Lo

ng

Dis

tan

ce

Cost ($)

040

80

120

160

14

12

10 8 6 4 2

x

y

O

x

y

Ox

y

O

3-1

Practi

ce

Gra

ph

ing

Lin

ear

Eq

uati

on

s

n

o

yes;

4x

- y

= 2

; y

es;

7x

= -

3;

x:

1 −

2 ;

y: -

2

x:

-3 −

7 ;

y:

no

ne

y

es;

3x

+ 2

y =

5;

yes;

3x

- 4

y =

12;

n

o

x

: 5 −

3 ; y

: 5

2

x:

4;

y: -

3

(0,

4.9

5)

$11.9

5

betw

een

6 h

an

d 7

h

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 3-1

Ch

ap

ter

3

9

Gle

ncoe A

lgeb

ra 1

1.FO

OT

BA

LL

On

e fo

otball

sea

son

, th

e C

aro

lin

a P

an

ther

s w

on 4

mor

e gam

es

than

th

ey l

ost.

Th

is c

an

be

rep

rese

nte

d

by y

= x

+ 4

, w

her

e x i

s th

e n

um

ber

of

gam

es l

ost

an

d y

is

the

nu

mber

of

gam

es

won

. W

rite

th

is l

inea

r eq

uati

on i

n

stan

dard

for

m.

2. T

OW

ING

Pic

k-M

-Up

Tow

ing C

omp

an

y

charg

es $

40 t

o h

ook

a c

ar

an

d $

1.7

0 f

or

each

mil

e th

at

it i

s to

wed

. T

he

equ

ati

on

y =

1.7

x +

40 r

epre

sen

ts t

he

tota

l co

st y

fo

r x m

iles

tow

ed.

Det

erm

ine

the

y-i

nte

rcep

t. D

escr

ibe

wh

at

the

valu

e m

ean

s in

th

is c

onte

xt.

3. S

HIP

PIN

G T

he

OO

CL

Sh

enzh

en,

one

of

the

wor

ld’s

larg

est

con

tain

er s

hip

s,

carr

ies

8063 T

EU

s (1

280 c

ubic

fee

t co

nta

iner

s).

Wor

ker

s ca

n u

nlo

ad

a s

hip

at

a r

ate

of

a T

EU

ever

y m

inu

te.

Usi

ng

this

rate

, w

rite

an

d g

rap

h a

n e

qu

ati

on t

o d

eter

min

e h

ow m

an

y h

ours

it

wil

l ta

ke

the

wor

ker

s to

un

load

half

of

the

con

tain

ers

from

th

e S

hen

zhen

.

4. B

US

INE

SS

Th

e eq

uati

on

y =

1000

x -

5000 r

epre

sen

ts t

he

mon

thly

pro

fits

of

a s

tart

-up

dry

cl

ean

ing c

omp

an

y.

Tim

e in

mon

ths

is

x a

nd

pro

fit

in d

olla

rs i

s y.

Th

e fi

rst

date

of

oper

ati

on i

s w

hen

tim

e is

zer

o.

How

ever

, p

rep

ara

tion

for

op

enin

g t

he

bu

sin

ess

beg

an

3 m

onth

s ea

rlie

r w

ith

th

e p

urc

hase

of

equ

ipm

ent

an

d s

up

pli

es.

Gra

ph

th

e li

nea

r fu

nct

ion

for

x-v

alu

es

from

-3 t

o 8.

5. B

ON

E G

RO

WT

H

Th

e h

eigh

t of

a

wom

an

can

be

pre

dic

ted

by t

he

equ

ati

on

h =

81.2

+ 3

.34r,

wh

ere

h i

s h

er h

eigh

t in

ce

nti

met

ers

an

d r

is

the

len

gth

of

her

ra

diu

s bon

e in

cen

tim

eter

s.

a.

Is t

his

is

a l

inea

r fu

nct

ion

? E

xp

lain

.

b.

Wh

at

are

th

e r-

an

d h

-in

terc

epts

of

the

equ

ati

on?

Do

they

mak

e se

nse

in

th

e si

tuati

on?

Exp

lain

.

c.

Use

th

e fu

nct

ion

to

fin

d t

he

ap

pro

xim

ate

hei

gh

t of

a w

oman

wh

ose

rad

ius

bon

e is

25 c

enti

met

ers

lon

g.

y

x2

46

8

O

2000

-2000

-4000

-6000

-8000

Tim

e (

ho

urs

)

20

10

040

30

y

x50

60

70

80

TEUs on Ship (thousands)

34 2 1589 7 6

3-1

Wo

rd

Pro

ble

m P

racti

ce

Gra

ph

ing

Lin

ear

Eq

uati

on

s

x -

y = -

4

T

he y

-in

terc

ep

t is

40,

wh

ich

is t

he

fee t

o h

oo

k t

he c

ar.

y

= 8

063

- 6

0x;

ab

ou

t 67.4

ho

urs

, o

r 67 h

ou

rs a

nd

21.5

min

ute

s

y

es;

the e

qu

ati

on

can

be w

ritt

en

in

sta

nd

ard

fo

r w

here

A =

1,

B = -

3.3

4,

an

d C

= 8

1.2

.

y-i

nte

rcep

t =

81.2

; x-i

nte

rcep

t ≈

-

24.3

; n

o -

we w

ou

ld e

xp

ect

a

wo

man

81.2

cm

tall t

o h

ave a

rms,

an

d a

neg

ati

ve r

ad

ius l

en

gth

has

no

real

mean

ing

.

165 c

m

Answers (Lesson 3-1)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A4 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

10

Gle

ncoe A

lgeb

ra 1

Tra

nsla

tin

g L

inear

Gra

ph

sL

inea

r gra

ph

s ca

n b

e tr

an

sla

ted

on

th

e co

ord

inate

pla

ne.

Th

is m

ean

s th

at

the

gra

ph

mov

es

up

, d

own

, ri

gh

t, o

r le

ft w

ith

out

chan

gin

g i

ts d

irec

tion

.

Tra

nsl

ati

ng t

he

gra

ph

s u

p o

r d

own

aff

ects

th

e y-c

oord

inate

for

a g

iven

x v

alu

e. T

ran

slati

ng

the

gra

ph

rig

ht

or l

eft

aff

ects

th

e x-c

oord

inate

for

a g

iven

y-v

alu

e.

T

ra

nsl

ate

th

e g

ra

ph

of y =

2x

+ 2

, 3 u

nit

s u

p.

Exerc

ises

Gra

ph

th

e f

un

cti

on

an

d t

he t

ra

nsl

ati

on

on

th

e s

am

e c

oo

rd

ina

te p

lan

e.

1. y

= x

+ 4

, 3 u

nit

s d

own

2. y

= 2

x –

2, 2

un

its

left

3. y

= -

2x

+ 1

, 1

un

it r

igh

t 4. y

= -

x -

3, 2

un

its

up

Add 3

to

each

y-v

alu

e.

y

xO

y=

2x

+ 2

y

xO

y=

x+

4

y

xO

y=

2x

- 2

y

xO

y=

-2

x+

1

y

xO

y=

-x

- 3

3-1

En

rich

men

t

y =

2x +

2

xy

-1

0

02

14

26

Tra

nsla

tio

n

xy

-1

3

05

17

29

Exam

ple

Lesson 3-1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

11

Gle

ncoe A

lgeb

ra 1

In a

dd

itio

n t

o or

gan

izin

g d

ata

, a s

pre

ad

shee

t ca

n b

e u

sed

to

rep

rese

nt

data

gra

ph

icall

y.

Exerc

ises

1. A

ph

oto

pri

nte

r of

fers

a s

ubsc

rip

tion

for

dig

ital

ph

oto

fin

ish

ing.

Th

e su

bsc

rip

tion

cos

ts

$4.9

9 p

er m

onth

. E

ach

sta

nd

ard

siz

e p

hot

o a s

ubsc

riber

pri

nts

cos

ts $

0.1

9.

Use

a

spre

ad

shee

t to

gra

ph

th

e eq

uati

on y

= 4

.99

+ 0

.19

x,

wh

ere

x i

s th

e n

um

ber

of

ph

otos

p

rin

ted

an

d y

is

the

tota

l m

onth

ly c

ost.

2. A

lon

g d

ista

nce

ser

vic

e p

lan

in

clu

des

a $

8.9

5 p

er m

onth

fee

plu

s $0.0

5 p

er m

inu

te o

f ca

lls.

Use

a s

pre

ad

shee

t to

gra

ph

th

e eq

uati

on y

= 8

.95

+ 0

.05

x,

wh

ere

x i

s th

e n

um

ber

of

min

ute

s of

call

s an

d y

is

the

tota

l m

onth

ly c

ost.

A

n i

nte

rn

et

reta

iler c

ha

rg

es

$1.9

9 p

er o

rd

er p

lus

$0.9

9 p

er i

tem

to

sh

ip b

oo

ks

an

d C

Ds.

Gra

ph

th

e e

qu

ati

on

y =

1.9

9 +

0.9

9x,

wh

ere x

is

the n

um

ber o

f it

em

s o

rd

ered

an

d y

is

the s

hip

pin

g c

ost

.

Ste

p 1

U

se c

olu

mn

A f

or t

he

nu

mber

s of

ite

ms

an

d

colu

mn

B f

or t

he

ship

pin

g c

osts

.

Ste

p 2

C

reate

a g

rap

h f

rom

th

e d

ata

. S

elec

t th

e d

ata

in

col

um

ns

A a

nd

B a

nd

sel

ect

Ch

art

fro

m t

he

Inse

rt m

enu

. S

elec

t an

XY

(S

catt

er)

chart

to

show

th

e d

ata

poi

nts

con

nec

ted

wit

h l

ine

segm

ents

.

A1 4 5 6 7 8 9 10

11

122 3

B

Sh

ipp

ing

.xls

Item

sS

hip

pin

g C

ost

1 2 3 4 5 6 7 8 9

10

$2.9

8

$3.9

7

$4.9

6

$5.9

5

$6.9

4

$7.9

3

$8.9

2

$9.9

1

$10.9

0

$11.8

9

Sh

eet

1S

heet

2S

heet

3-1

Sp

read

sheet

Act

ivit

y

Lin

ear

Eq

uati

on

s

Exam

ple

See s

tud

en

ts’

wo

rk.

See s

tud

en

ts’

wo

rk.

Answers (Lesson 3-1)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A5 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

12

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

So

lvin

g L

inear

Eq

uati

on

s b

y G

rap

hin

g

So

lve b

y G

rap

hin

g

You

can

sol

ve

an

equ

ati

on b

y g

rap

hin

g t

he

rela

ted

fu

nct

ion

. T

he

solu

tion

of

the

equ

ati

on i

s th

e x-i

nte

rcep

t of

th

e fu

nct

ion

.

S

olv

e t

he e

qu

ati

on

2x -

2 =

-4 b

y g

ra

ph

ing

.

Fir

st s

et t

he

equ

ati

on e

qu

al

to 0

. T

hen

rep

lace

0 w

ith

f(x

). M

ak

e a t

able

of

ord

ered

pair

so

luti

ons.

Gra

ph

th

e fu

nct

ion

an

d l

ocate

th

e x-i

nte

rcep

t.

2x -

2 =

-4

2x -

2 +

4 =

-4 +

4

2

x +

2 =

0

f(x

) =

2x +

2

To

gra

ph

th

e fu

nct

ion

, m

ak

e a t

able

. G

rap

h t

he

ord

ered

pair

s.

xf(

x) =

2x +

2f(

x)

[x,

f(x)]

1f(

1)

= 2

(1)

+ 2

4(1

, 4)

-1

f(-

1)

= 2

(-1)

+ 2

0(-

1,

0)

-2

f(-

2)

= 2

(-2)

+ 2

-

2(-

2,

-2)

y

x

Th

e gra

ph

in

ters

ects

th

e x-a

xis

at

(-1,

0).

Th

e so

luti

on t

o th

e eq

uati

on i

s x =

-1.

Exerc

ises

So

lve e

ach

eq

ua

tio

n.

1. 3

x -

3 =

0 1

2.

-2

x +

1 =

5 -

2x

3.

-x +

4 =

0 4

y

x

y

x

y

x

4. 0 =

4x -

1

1 −

4

5. 5

x -

1 =

5x

6.

-3x +

1 =

0

1 −

3

y

x

y

x

y

x

3-2

Origin

al equation

Add 4

to e

ach s

ide.

Sim

plif

y.

Repla

ce 0

with f

(x).

Exam

ple

Lesson 3-2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

13

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n (c

on

tin

ued

)

So

lvin

g L

inear

Eq

uati

on

s b

y G

rap

hin

g

Est

imate

So

luti

on

s b

y G

rap

hin

g

Som

etim

es g

rap

hin

g d

oes

not

pro

vid

e an

exact

so

luti

on,

bu

t on

ly a

n e

stim

ate

. In

th

ese

case

s, s

olve

alg

ebra

icall

y t

o fi

nd

th

e ex

act

sol

uti

on.

W

ALK

ING

Y

ou

an

d y

ou

r c

ou

sin

decid

e t

o w

alk

th

e 7

-mil

e t

ra

il a

t

the s

tate

pa

rk

to

th

e r

an

ger s

tati

on

. T

he f

un

cti

on

d =

7 –

3.2t r

ep

resen

ts y

ou

r

dis

tan

ce d

fro

m t

he r

an

ger s

tati

on

aft

er t

ho

urs.

Fin

d t

he z

ero

of

this

fu

ncti

on

.

Describ

e w

ha

t th

is v

alu

e m

ea

ns i

n t

his

co

nte

xt.

Mak

e a t

able

of

valu

es t

o gra

ph

th

e fu

nct

ion

.

t

d =

7 -

3.2

td

(t,

d)

0d

= 7

- 3

.2(0

) 7

(0

, 7)

1d

= 7

- 3

.2(1

)3.8

(1,

3.8

)

2d

= 7

- 3

.2(2

)0.6

(2,

0.6

)

Miles from Ranger Station

23 1

0

45678y

Tim

e (h

ours

)

21

x3

Th

e gra

ph

in

ters

ects

th

e t–

axis

bet

wee

n t

= 2

an

d t

= 3

, bu

t cl

oser

to

t =

2.

It w

ill

tak

e you

an

d y

our

cou

sin

ju

st

over

tw

o h

ours

to

reach

th

e ra

nger

sta

tion

.

You

can

ch

eck

you

r es

tim

ate

by s

olvin

g t

he

equ

ati

on a

lgeb

raic

all

y.

Exerc

ises

1. M

US

IC Jes

sica

wan

ts t

o re

cord

her

favor

ite

son

gs

to

one

CD

. T

he

fun

ctio

n C

= 8

0 -

3.2

2n

rep

rese

nts

th

e re

cord

ing

tim

e C

avail

able

aft

er n

son

gs

are

rec

ord

ed.

Fin

d t

he

zero

of

this

fu

nct

ion

. D

escr

ibe

wh

at

this

valu

e m

ean

s in

th

is c

onte

xt.

ju

st

un

der

25;

on

ly 2

4 s

on

gs c

an

be r

eco

rded

on

on

e C

D

2

. G

IFT

CA

RD

S E

nri

qu

e u

ses

a g

ift

card

to

bu

y c

offe

e at

a

coff

ee s

hop

. T

he

init

ial

valu

e of

th

e gif

t ca

rd i

s $20.

Th

e fu

nct

ion

n =

20 –

2.7

5c

rep

rese

nts

th

e am

oun

t of

mon

ey s

till

le

ft o

n t

he

gif

t ca

rd n

aft

er p

urc

hasi

ng c

cu

ps

of c

offe

e. F

ind

th

e ze

ro o

f th

is f

un

ctio

n.

Des

crib

e w

hat

this

valu

e m

ean

s in

th

is c

onte

xt.

ju

st

over

7;

En

riq

ue c

an

bu

y 7

cu

ps o

f co

ffee

wit

h t

he g

ift

card

Value Left on Card ($)

4 08

12

16

20

24

Coff

ees

Bough

t

24

68

10

12

3-2

Time Available (min)

10 0

20

30

40

50

60

70

80

90

Num

ber

of

Songs

510

15

20

25

30

Exam

ple

Answers (Lesson 3-2)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A6 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

14

Gle

ncoe A

lgeb

ra 1

Sk

ills

Practi

ce

So

lvin

g L

inear

Eq

uati

on

s b

y G

rap

hin

gS

olv

e e

ach

eq

ua

tio

n.

1. 2

x -

5 =

-3 +

2x

2.

-3

x +

2 =

0

3. 3

x +

2 =

3x -

1

y

x

y

x

y

x

4. 4

x -

1 =

4x +

2

5. 4x -

1 =

0

6. 0 =

5x +

3

y

x

y

x

y

x

7. 0 =

-2

x +

4

8.

-3

x +

8 =

5 -

3x

9.

-x +

1 =

0

y

x

y

x

y

x

10. G

IFT

CA

RD

S Y

ou

rece

ive a

gif

t ca

rd f

or

trad

ing c

ard

s fr

om

a l

oca

l st

ore

. T

he f

un

ctio

n

d =

20 –

1.9

5c r

ep

rese

nts

th

e r

em

ain

ing d

oll

ars

d o

n t

he g

ift

card

aft

er

obta

inin

g c

pack

ages

of

card

s. F

ind

th

e z

ero

of

this

fu

nct

ion

. D

esc

ribe

wh

at

this

valu

e m

ean

s in

th

is c

on

text.

10.2

6;

yo

u c

an

pu

rch

ase 1

0 p

ackag

es

of

trad

ing

card

s w

ith

th

e g

ift

card

.

3-2

Amount Remaining on Gift Card ($)

2 0468

10

12

14

16

18

20d

Pac

kage

s of

Car

ds

Bough

t

12

34

56

78

910

c

d=

20

- 1

.95c

no

so

luti

on

2 −

3

no

so

luti

on

no

so

luti

on

1 −

4

- 3

5

no

so

luti

on

21

Lesson 3-2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

15

Gle

ncoe A

lgeb

ra 1

Practi

ce

So

lvin

g L

inear

Eq

uati

on

s b

y G

rap

hin

gS

olv

e e

ach

eq

ua

tio

n.

1. 1

2 x

- 2

= 0

4

2

. -

3x +

2 =

-1

1

3. 4x -

2 =

-2

0

y

x

y

x

y

x

4. 1

3 x

+ 2

= 1

3 x

- 1

5

. 2

3 x

+ 4

= 3

6

. 3

4 x

+ 1

= 3

4 x

- 7

n

o s

olu

tio

n

- 3

2

no

so

luti

on

y

x

y

x

y

x

So

lve e

ach

eq

ua

tio

n b

y g

ra

ph

ing

. V

erif

y y

ou

r a

nsw

er a

lgeb

ra

ica

lly

7. 13

x +

2 =

11x -

1

8.

-9x -

3 =

-4

x -

3

9.

- 1

3 x

+ 2

= 2

3 x

- 1

-

3 −

2

0

3

y

x

y

x

y

x

10. D

IST

AN

CE

A

bu

s is

dri

vin

g a

t 60 m

iles

per

hou

r

tow

ard

a b

us

stati

on

th

at

is 2

50 m

iles

aw

ay.

Th

e

fun

ctio

n d

= 2

50 –

60t

rep

rese

nts

th

e d

ista

nce

d f

rom

the b

us

stati

on

th

e b

us

is t

hou

rs a

fter

it h

as

start

ed

dri

vin

g.

Fin

d t

he z

ero

of

this

fu

nct

ion

. D

esc

ribe w

hat

this

valu

e m

ean

s in

th

is c

on

text.

Distance from BusStation (miles)

50 0

100

150

200

250

300

Tim

e (h

ours

)

12

34

56

3-2 ≈

4.1

7 h

r; t

he b

us w

ill

ari

ve a

t th

e s

tati

on

in

ap

pro

xim

ate

ly 4

.17 h

ou

rs.

Answers (Lesson 3-2)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A7 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

16

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

So

lvin

g L

inear

Eq

uati

on

s b

y G

rap

hin

g

1. P

ET

CA

RE

You

bu

y a

6.3

-pou

nd

bag

of d

ry c

at

food

for

you

r ca

t. T

he

fun

ctio

n

c=

6.3

– 0

.25p

rep

rese

nts

th

e am

oun

t of

ca

t fo

od c

rem

ain

ing i

n t

he

bag w

hen

th

e ca

t is

fed

th

e sa

me

am

oun

t ea

ch d

ay f

or

p d

ays.

Fin

d t

he

zero

of

this

fu

nct

ion

. D

escr

ibe

wh

at

this

valu

e m

ean

s in

th

is c

onte

xt.

2. S

AV

ING

S J

essi

ca i

s sa

vin

g f

or c

olle

ge

usi

ng a

dir

ect

dep

osit

fro

m h

er p

aych

eck

in

to a

savin

gs

acc

oun

t. T

he

fun

ctio

n

m =

3045 -

52.5

0t

rep

rese

nts

th

e am

oun

t of

mon

ey m

sti

ll n

eed

ed a

fter

t

wee

ks.

Fin

d t

he

zero

of

this

fu

nct

ion

. W

hat

doe

s th

is v

alu

e m

ean

in

th

is

con

text?

3. FIN

AN

CE

Mic

hael

bor

row

s $100 f

rom

h

is d

ad

. T

he

fun

ctio

n v

= 1

00 -

4.7

5p

re

pre

sen

ts t

he

outs

tan

din

g b

ala

nce

v a

fter

p w

eek

ly p

aym

ents

. F

ind

th

e ze

ro o

f th

is f

un

ctio

n.

Des

crib

e w

hat

this

valu

e m

ean

s in

th

is c

onte

xt.

4. B

AK

E S

ALE

A

shle

y h

as

$15 i

n t

he

Pep

C

lub t

reasu

ry t

o p

ay f

or s

up

pli

es f

or a

ch

ocol

ate

ch

ip c

ook

ie b

ak

e sa

le.

Th

e fu

nct

ion

d =

15 –

0.0

8c

rep

rese

nts

th

e d

olla

rs d

lef

t in

th

e cl

ub t

reasu

ry a

fter

m

ak

ing c

coo

kie

s. F

ind

th

e ze

ro o

f th

is

fun

ctio

n.

Wh

at

doe

s th

is v

alu

e re

pre

sen

t in

th

is c

onte

xt?

5

. D

EN

TA

L H

YG

IEN

EY

ou a

re p

ack

ing

you

r su

itca

se t

o go

aw

ay t

o a 1

4-d

ay

sum

mer

cam

p.

Th

e st

ore

carr

ies

thre

e si

zes

of t

ubes

of

toot

hp

ast

e.

Tu

be

Siz

e

(ou

nces)

Siz

e

(gra

ms)

A0.7

521.2

6

B0.9

25.5

2

C3.0

85.0

4

So

urc

e:

National A

cadem

y o

f S

cie

nces

a.

Th

e fu

nct

ion

n=

21.2

6 -

0.8

b

rep

rese

nts

th

e n

um

ber

of

rem

ain

ing

bru

shin

gs

n u

sin

g b

gra

ms

per

bru

shin

g u

sin

g T

ube

A.

Fin

d t

he

zero

of

th

is f

un

ctio

n.

Des

crib

e w

hat

this

valu

e m

ean

s in

th

is c

onte

xt.

b.

Th

e fu

nct

ion

n=

25.5

2 –

0.8

b

rep

rese

nts

th

e n

um

ber

of

rem

ain

ing

bru

shin

gs

n u

sin

g b

gra

ms

per

bru

shin

g u

sin

g T

ube

B.

Fin

d t

he

zero

of

th

is f

un

ctio

n.

Des

crib

e w

hat

this

valu

e m

ean

s in

th

is c

onte

xt.

c.

Wri

te a

fu

nct

ion

to

rep

rese

nt

the

nu

mber

of

rem

ain

ing b

rush

ings

n u

sin

g b

gra

ms

per

bru

shin

g u

sin

g

Tu

be

C.

Fin

d t

he

zero

of

this

fu

nct

ion

. D

escr

ibe

wh

at

this

valu

e m

ean

s in

th

is c

onte

xt.

d.

If y

ou w

ill

bru

sh y

our

teet

h t

wic

e ea

ch

day w

hil

e at

cam

p,

wh

ich

is

the

small

est

tube

of t

ooth

past

e you

can

ch

oose

? E

xp

lain

you

r re

aso

nin

g.

3-2 25.2

; T

here

are

25 f

ull s

erv

ing

s

of

cat

foo

d i

n t

heb

ag

.

58;

It w

ill

take 5

8 w

eeks f

or

Jessic

a t

o s

ave t

he m

on

ey s

he

need

s.

$21.0

5;

Aft

er

21 w

eeks,

he w

ill

have p

aid

back 2

1 ×

4.7

5,

or

$99.7

5.

He p

ays $

0.2

5 o

n w

eek 2

2.

187.5

, S

he b

reaks e

ven

at

188 c

oo

kie

s.

n =

85.0

4 -

0.8

b;

106;

Tu

be C

w

ill

pro

vid

e 1

06 b

rush

ing

s.

31.9

; T

ub

e B

will

pro

vid

e

31 b

rush

ing

s.

26.5

75;

Tu

be A

will

pro

vid

e

26 b

rush

ing

s.

Tu

be B

; Y

ou

need

28 b

rush

ing

s.

Tu

be A

is n

ot

en

ou

gh

an

d

Tu

be C

is t

oo

mu

ch

.

Lesson 3-2

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

17

Gle

ncoe A

lgeb

ra 1

3-2

En

ric

hm

en

t

Co

mp

osit

e F

un

cti

on

s

Th

ree

thin

gs

are

nee

ded

to

have

a f

un

ctio

n—

a s

et c

all

ed t

he

dom

ain

, a s

et c

all

ed t

he

ran

ge,

an

d a

ru

le t

hat

matc

hes

each

ele

men

t in

th

e d

omain

wit

h o

nly

on

e el

emen

t in

th

e ra

nge.

Her

e is

an

exam

ple

.

Ru

le:

f(x) =

2x +

1

3

-5

f(x)

5

x 2

1

-3

f(x

) =

2x +

1

f(1

) =

2(1

) +

1 =

2 +

1 =

3

f(2

) =

2(2

) +

1 =

4 +

1 =

5

f(-

3) =

2(-

3) +

1 =

26 +

1 =

-5

Su

pp

ose

we

have

thre

e se

ts A

, B

, an

d C

an

d t

wo

fun

ctio

ns

des

crib

ed

as

show

n b

elow

.

Ru

le:

f(x) =

2x +

1

Ru

le:

g(y

) =

3y -

4

AB

C

f(x) 3

5

x 1

g[f

(x)]

g

(y) =

3y -

4

g

(3) =

3(3

) -

4 =

5

Let

’s f

ind

a r

ule

th

at

wil

l m

atc

h e

lem

ents

of

set

A w

ith

ele

men

ts o

f se

t C

wit

hou

t fi

nd

ing a

ny e

lem

ents

in

set

B.

In o

ther

wor

ds,

let

’s f

ind

a r

ule

for

th

e co

mp

osit

e f

un

cti

on

g[f(x

)].

Sin

ce f

(x) =

2x +

1,

g[f

(x)]

= g

(2x +

1).

Sin

ce g

(y) =

3y -

4,

g(2

x +

1) =

3(2

x +

1) -

4,

or 6

x -

1.

Th

eref

ore,

g[f

(x)]

= 6

x -

1.

Fin

d a

ru

le f

or t

he c

om

po

sit

e f

un

cti

on

g[f

(x)]

.

1. f(

x) =

3x a

nd

g(y

) =

2y +

1

2. f(

x) 5 x

2 +

1 a

nd

g(y

) =

4y

3. f(

x) =

-2x a

nd

g(y

) =

y2 -

3y

4. f(

x) =

1 −

x - 3

an

d g

(y) =

y-

1

5. Is

it

alw

ays

the

case

th

at

g[f

(x)]

= f

[g(x

)]?

Ju

stif

y y

our

an

swer

.

g[f

(x)]

= 6

x +

1

g[f

(x)]

= 4

x2 +

4

g[f

(x)]

= 4

x2 +

6x

g[f

(x)]

= x

- 3

N

o.

Fo

r exam

ple

, in

Exerc

ise 1

,

f[g

(x)]

= f

(2x +

1)

= 3

(2x +

1)

= 6

x +

3,

no

t 6x +

1.

Answers (Lesson 3-2)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A8 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

18

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Rate

of

Ch

an

ge a

nd

Slo

pe

3-3

Rate

of

Ch

an

ge

Th

e r

ate

of

ch

an

ge t

ell

s, o

n a

vera

ge,

how

a q

uan

tity

is

chan

gin

g

over

tim

e.

PO

PU

LA

TIO

N T

he g

ra

ph

sh

ow

s t

he p

op

ula

tio

n g

ro

wth

in

Ch

ina

.

a

. F

ind

th

e r

ate

s o

f ch

an

ge f

or 1

950–1975 a

nd

fo

r

2000–2025.

1950–1975:

chan

ge i

n p

op

ula

tion

ch

an

ge i

n t

ime

=

0.9

3 -

0.5

5

1975 -

1950

= 0

.38

25 o

r 0.0

152

2000–2025:

chan

ge i

n p

op

ula

tion

ch

an

ge i

n t

ime

=

1.4

5 -

1.2

7

2025 -

2000

= 0

.18

25 o

r 0.0

072

b

. E

xp

lain

th

e m

ea

nin

g o

f th

e r

ate

of

ch

an

ge i

n e

ach

ca

se.

Fro

m 1

950–1975,

the g

row

th w

as

0.0

152 b

illi

on

per

year,

or

15.2

mil

lion

per

year.

Fro

m 2

000–2025,

the g

row

th i

s exp

ect

ed

to b

e 0

.0072 b

illi

on

per

year,

or

7.2

mil

lion

p

er

year.

c.

Ho

w a

re t

he d

iffe

ren

t ra

tes o

f ch

an

ge s

ho

wn

on

th

e g

ra

ph

?

Th

ere

is

a g

reate

r vert

ical

chan

ge f

or

1950–1975 t

han

for

2000–2025.

Th

ere

fore

, th

e

sect

ion

of

the g

rap

h f

or

1950–1975 h

as

a s

teep

er

slop

e.

Exerc

ises

1. LO

NG

EV

ITY

T

he g

rap

h s

how

s th

e p

red

icte

d l

ife

exp

ect

an

cy f

or

men

an

d w

om

en

born

in

a g

iven

year.

a

. F

ind

th

e r

ate

s of

chan

ge f

or

wom

en

fro

m 2

000–2025

an

d 2

025–2050.

0.1

6/y

r, 0

.12/y

r

b

. F

ind

th

e r

ate

s of

chan

ge f

or

men

fro

m 2

000–2025 a

nd

2025–2050.

0.1

6/y

r, 0

.12/y

r

c.

Exp

lain

th

e m

ean

ing o

f you

r re

sult

s in

Exerc

ises

1

an

d 2

. B

oth

men

an

d w

om

en

in

cre

ased

th

eir

life

exp

ecta

ncy a

t th

e s

am

e r

ate

s.

d

. W

hat

patt

ern

do y

ou

see i

n t

he i

ncr

ease

wit

h e

ach

25-y

ear

peri

od

? W

hile l

ife e

xp

ecta

ncy

incre

ases,

it d

oes n

ot

incre

ase a

t a

co

nsta

nt

rate

.

e.

Mak

e a

pre

dic

tion

for

the l

ife e

xp

ect

an

cy f

or

2050–2075.

Exp

lain

how

you

arr

ived

at

you

r p

red

icti

on

. S

am

ple

an

sw

er:

89 f

or

wo

men

an

d 8

3 f

or

men

; th

e

decre

ase i

n r

ate

fro

m 2

000–2025 t

o 2

025–2050 i

s 0

.04/y

r. I

f th

e d

ecre

ase

in t

he r

ate

rem

ain

s t

he s

am

e,

the c

han

ge o

f ra

te f

or

2050–2075 m

igh

t b

e

0.0

8/y

r an

d 2

5(0

.08) =

2 y

ears

of

incre

ase o

ver

the 2

5-y

ear

sp

an

.

Pre

dic

tin

g L

ife E

xp

ecta

ncy

Year

Bo

rn

Age

2000

Women

Men

100

95

90

85

80

75

70

65

2050*

2025*

*Estim

ated

So

urc

e:

USA

TO

DA

Y80

84

81

78

74

87

Po

pu

lati

on

Gro

wth

in

Ch

ina

Year

People (billions)

1950

1975

2000

2.0

1.5

1.0

0.5 0

2025*

*Estim

ated

So

urc

e:

Uni

ted

Nat

ions

Pop

ulat

ion

Div

isio

n

0.55

0.93

1.27

1.45

Exam

ple

Lesson 3-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

19

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n (c

on

tin

ued

)

Rate

of

Ch

an

ge a

nd

Slo

pe

3-3

Fin

d S

lop

e

Th

e s

lop

e o

f a l

ine i

s th

e r

ati

o o

f ch

an

ge i

n t

he y

- coord

inate

s (r

ise)

to t

he

chan

ge i

n t

he x

- coord

inate

s (r

un

) as

you

move i

n t

he p

osi

tive d

irect

ion

.

Slo

pe o

f a L

ine

m =

rise

run o

r m

= y

2 -

y 1

x 2 -

x 1 , w

here

(x

1,

y1)

and (

x2,

y2)

are

the c

oord

inate

s

of

any t

wo p

oin

ts o

n a

nonvert

ical lin

e

F

ind

th

e s

lop

e o

f th

e

lin

e t

ha

t p

asses t

hro

ug

h (-

3,

5)

an

d

(4, -

2).

Let

(-3,

5)

= (

x1,

y1)

an

d

(4,

-2)

= (

x2,

y2).

m =

y2 -

y1

x2 -

x1

S

lope f

orm

ula

=

-

2 -

5

-4 (

-3)

y 2 =

-2,

y 1 =

5,

x 2 =

4,

x 1 =

-3

=

-7

7

Sim

plif

y.

=

-1

Exerc

ises

Fin

d t

he s

lop

e o

f th

e l

ine t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts.

1. (4

, 9),

(1,

6)

1

2. (-

4,

-1),

(-

2,

-5) -

2

3. (-

4,

-1),

(-

4,

-5)

u

nd

efi

ned

4. (2

, 1),

(8,

9)

4 −

3

5. (1

4,

-8),

(7,

-6) -

2 −

7

6. (4

, -

3),

(8,

-3)

0

7. (1

, -

2),

(6,

2)

4 −

5

8. (2

, 5),

(6,

2) -

3 −

4

9. (4

, 3.5

), (

-4,

3.5

) 0

Fin

d t

he v

alu

e o

f r s

o t

he l

ine t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts h

as t

he

giv

en

slo

pe.

10. (6

, 8),

(r,

-2),

m =

1 -

4

11. (-

1,

-3),

(7,

r),

m =

3

4 3

12. (2

, 8),

(r,

-4)

m =

-3 6

13. (7

, -

5),

(6,

r),

m =

0 -

5

14. (r

, 4),

(7,

1),

m =

3

4 11

15. (7

, 5),

(r,

9),

m =

6 2

3 −

3

F

ind

th

e v

alu

e o

f r s

o t

ha

t th

e l

ine t

hro

ug

h (

10, r)

an

d (

3,

4)

ha

s a

slo

pe o

f -

2

7 .

m

= y

2 -

y1

x2 -

x1

Slo

pe f

orm

ula

-

2

7 =

4 -

r

3 -

10

m =

- 2

7 ,

y2 =

4,

y1 =

r,

x2 =

3,

x1 =

10

-

2

7 =

4 -

r

-7

Sim

plif

y.

-2(-

7)

= 7

(4 -

r)

Cro

ss m

ultip

ly.

14 =

28

- 7

r D

istr

ibutive P

ropert

y

-

14 =

-7

r S

ubtr

act

28 f

rom

each s

ide.

2 =

r

Div

ide e

ach s

ide b

y -

7.

Exam

ple

1Exam

ple

2

Answers (Lesson 3-3)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A9 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

20

Gle

ncoe A

lgeb

ra 1

Sk

ills

Practi

ce

Rate

of

Ch

an

ge a

nd

Slo

pe

3-3

Fin

d t

he s

lop

e o

f th

e l

ine t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts.

1.

( 0,

1)

( 2,

5)

x

y O

2.

( 0,

0)

( 3,

1)

x

y

O

3.

( 0,

1) ( 1,-

2)

x

y

O

2

1

3

-3

4. (2

, 5),

(3,

6)

1

5. (6

, 1),

(-

6,

1)

0

6. (4

, 6),

(4,

8)

un

defi

ned

7. (5

, 2),

(5,

-2)

un

defi

ned

8. (2

, 5),

(-

3,

-5)

2

9. (9

, 8),

(7,

-8)

8

10. (-

5,

-8),

(-

8,

1) -

3

11. (-

3,

10),

(-

3,

7)

un

defi

ned

12. (1

7,

18),

(18,

17) -

1

13. (-

6,

-4),

(4,

1)

1

2

14. (1

0,

0),

(-

2,

4) -

1 −

3

15. (2

, -

1),

(-

8,

-2)

1 −

10

16. (5

, -

9),

(3,

-2) -

7 −

2

17. (1

2,

6),

(3,

-5)

11 −

9

18. (-

4,

5),

(-

8,

-5)

5

2

19. (-

5,

6),

(7,

-8) -

7 −

6

Fin

d t

he v

alu

e o

f r s

o t

he l

ine t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts

ha

s t

he g

iven

slo

pe.

20. (r

, 3),

(5,

9),

m =

2 2

21. (5

, 9),

(r,

-3),

m =

-4 8

22. (r

, 2),

(6,

3),

m =

1

2 4

23. (r

, 4),

(7,

1),

m =

3

4

11

24. (5

, 3),

(r,

-5),

m =

4 3

25. (7

, r)

, (4

, 6),

m =

0 6

Lesson 3-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

21

Gle

ncoe A

lgeb

ra 1

Practi

ce

Rate

of

Ch

an

ge a

nd

Slo

pe

3-3

Fin

d t

he s

lop

e o

f th

e l

ine t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts.

1.

( –1

, 0

)

( –2

, 3

)

x

y

O

2.

3.

( –2

, 3

)

( 3,

3)

x

y O

-

3

4 −

5

0

4. (6

, 3),

(7,

-4) -

7

5. (-

9,

-3),

(-

7,

-5) -

1

6. (6

, -

2),

(5,

-4)

2

7. (7

, -

4),

(4,

8) -

4

8. (-

7,

8),

(-

7,

5)

un

defi

ned

9. (5

, 9),

(3,

9)

0

10. (1

5,

2),

(-

6,

5) -

1 −

7

11. (3

, 9),

(-

2,

8)

1 −

5

12. (-

2,

-5),

(7,

8)

13 −

9

13. (1

2,

10),

(12,

5)

un

defi

ned

14. (0

.2,

-0.9

), (

0.5

, -

0.9

) 0

15.

( 7

3 ,

4

3 ) ,

(- 1

3 ,

2

3 )

1

4

Fin

d t

he v

alu

e o

f r s

o t

he l

ine t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts h

as t

he

giv

en

slo

pe.

16. (-

2, r)

, (6

, 7),

m =

1

2 3

17. (-

4,

3),

(r,

5),

m =

1

4 4

18. (-

3,

-4),

(-

5, r)

, m

= -

9

2 5

19.

(-5, r)

, (1

, 3),

m =

7

6 -

4

20. (1

, 4),

(r,

5),

m u

nd

efi

ned

1

21. (-

7,

2),

(-

8, r)

, m

= -

5 7

22. (r

, 7),

(11,

8),

m =

- 1

5 16

23. (r

, 2),

(5, r)

, m

= 0

2

24. R

OO

FIN

G T

he pitch

of

a r

oof

is t

he n

um

ber

of

feet

the r

oof

rise

s fo

r each

12 f

eet

hori

zon

tall

y.

If a

roof

has

a p

itch

of

8,

wh

at

is i

ts s

lop

e e

xp

ress

ed

as

a p

osi

tive n

um

ber?

2

3

25. S

ALE

S A

dail

y n

ew

spap

er

had

12,1

25 s

ubsc

ribers

wh

en

it

began

pu

bli

cati

on

. F

ive y

ears

la

ter

it h

ad

10,1

00 s

ubsc

ribers

. W

hat

is t

he a

vera

ge y

earl

y r

ate

of

chan

ge i

n t

he n

um

ber

of

subsc

ribers

for

the f

ive-y

ear

peri

od

? -

405 s

ub

scri

bers

per

year

( 3,

1)

( –2

, –

3)

x

y

O

Answers (Lesson 3-3)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A10 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

22

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Rate

of

Ch

an

ge a

nd

Slo

pe

3-3

1.H

IGH

WA

YS

Roa

dw

ay s

ign

s su

ch a

s th

e on

e bel

ow a

re u

sed

to

warn

dri

ver

s of

an

u

pco

min

g s

teep

dow

n g

rad

e th

at

cou

ld

lead

to

a d

an

ger

ous

situ

ati

on.

Wh

at

is

the

gra

de,

or

slop

e, o

f th

e h

ill

des

crib

ed

on t

he

sign

?2 − 25

2. A

MU

SE

ME

NT

PA

RK

S T

he

Sh

eiK

ra

roll

er c

oast

er a

t B

usc

h G

ard

ens

in

Tam

pa,

Flo

rid

a,

featu

res

a 1

38-f

oot

ver

tica

l d

rop

. W

hat

is t

he

slop

e of

th

e co

ast

er t

rack

at

this

part

of

the

rid

e?

Exp

lain

.

T

he s

lop

e i

s u

nd

efi

ned

becau

se

the d

rop

is v

ert

ical.

3. C

EN

SU

S T

he

table

sh

ows

the

pop

ula

tion

d

ensi

ty f

or t

he

state

of

Tex

as

in v

ari

ous

yea

rs.

Fin

d t

he

aver

age

an

nu

al

rate

of

chan

ge

in t

he

pop

ula

tion

den

sity

fro

m

2000 t

o 2006.

in

cre

ased

ab

ou

t 1.3

2 p

eo

ple

per

sq

uare

mile

4.R

EA

L E

ST

AT

E T

he

med

ian

pri

ce o

f an

ex

isti

ng s

ingle

-fam

ily h

ome

in t

he

Un

ited

S

tate

s w

as

$195,2

00 i

n 2

004.

Th

e m

edia

n

pri

ce h

ad

ris

en t

o $221,9

00 b

y 2

006.

Fin

d

the

aver

age

an

nu

al

rate

of

chan

ge

in

med

ian

hom

e p

rice

fro

m 2

004 t

o 2006.

$13,0

75

5. C

OA

L E

XP

OR

TS

Th

e gra

ph

sh

ows

the

an

nu

al

coal

exp

orts

fro

m U

.S.

min

es i

n

mil

lion

s of

sh

ort

ton

s.

So

urce:

Energ

y In

form

atio

n A

ssoci

atio

n

a.

Wh

at

was

the

rate

of

chan

ge

in c

oal

exp

orts

bet

wee

n 2

001 a

nd

2002?

-9 m

illio

n t

on

s p

er

year

or

- 9

1

b.

How

doe

s th

e ra

te o

f ch

an

ge

in c

oal

exp

orts

fro

m 2

005 t

o 2006 c

omp

are

to

that

of 2

001 t

o 2002?

In

2005–2006,

the r

ate

was

0 c

om

pare

d t

o -

9

1 i

n

2001–2002.

c.

Exp

lain

th

e m

ean

ing o

f th

e p

art

of

the

gra

ph

wit

h a

slo

pe

of z

ero.

Th

e s

lop

e i

nd

icate

s t

hat

there

w

as n

o c

han

ge i

n t

he a

mo

un

t o

f co

al

exp

ort

ed

betw

een

2005

an

d 2

006.

Million Short Tons

40

50

30 0

60

70

80

90

100

2004

2003

2000

2001

2002

2006

2005

Tota

l Exp

ort

s

Po

pu

lati

on

Den

sit

y

Year

Peo

ple

Per

Sq

uare

Mile

1930

22.1

1960

36.4

1980

54.3

2000

79.6

2006

87.5

So

urce:

Bure

au o

f th

e C

ensu

s, U

.S. D

ept.

of C

om

merc

e

Lesson 3-3

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

23

Gle

ncoe A

lgeb

ra 1

En

ric

hm

en

t 3-3

Tre

asu

re H

un

t w

ith

Slo

pes

Usin

g t

he d

efi

nit

ion

of

slo

pe,

dra

w s

eg

men

ts w

ith

th

e s

lop

es l

iste

d

belo

w i

n o

rd

er.

A c

orrect

so

luti

on

wil

l tr

ace t

he r

ou

te t

o t

he t

rea

su

re.

1. 3

2.

1

4

3.

- 2

5

4.

0

5. 1

6.

-1

7.

no

slop

e 8.

2

7

9.

3

2

10.

1

3

11.

- 3

4

12.

3

Sta

rt H

ere

Trea

sure

Answers (Lesson 3-3)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A11 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

24

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Dir

ect

Vari

ati

on

3-4

Dir

ect

Vari

ati

on

Eq

uati

on

s A

dir

ect

va

ria

tio

n i

s d

escr

ibed

by a

n e

qu

ati

on o

f th

e fo

rm y

= k

x,

wh

ere

k ≠

0.

We

say t

hat

y v

ari

es d

irec

tly a

s x.

In t

he

equ

ati

on y

= k

x,

k i

s th

e co

nsta

nt

of

va

ria

tio

n.

N

am

e t

he c

on

sta

nt

of

va

ria

tio

n f

or t

he e

qu

ati

on

. T

hen

fin

d

the s

lop

e o

f th

e l

ine t

ha

t p

asses

thro

ug

h t

he p

air

of

po

ints

.

For

y =

1 −

2 x

, th

e co

nst

an

t of

vari

ati

on i

s 1

2 .

m

= y

2 -

y 1 −

x 2 -

x 1

Slo

pe f

orm

ula

=

1 - 0 −

2 -

0

(x1,

y1) =

(0,

0),

(x

2,

y2) =

(2,

1)

=

1 −

2

Sim

plif

y.

Th

e sl

ope

is 1

2 .

S

up

po

se y

va

rie

s d

irectl

y

as x

, a

nd

y =

30 w

hen

x =

5.

a.

Writ

e a

dir

ect

va

ria

tio

n e

qu

ati

on

tha

t rela

tes x

an

d y

.

Fin

d t

he

valu

e of

k.

y =

kx

Direct

variation e

quation

30 =

k(5

) R

epla

ce y

with 3

0 a

nd x

with 5

.

6 =

k

Div

ide e

ach s

ide b

y 5

.

Th

eref

ore,

th

e eq

uati

on i

s y =

6x.

b.

Use t

he d

irect

va

ria

tio

n e

qu

ati

on

to

fin

d x

wh

en

y =

18.

y =

6x

Direct

variation e

quation

18 =

6x

Repla

ce y

with 1

8.

3 =

x

Div

ide e

ach s

ide b

y 6

.

Th

eref

ore,

x =

3 w

hen

y =

18.

Exerc

ises

Na

me t

he c

on

sta

nt

of

va

ria

tio

n f

or e

ach

eq

ua

tio

n.

Th

en

dete

rm

ine t

he s

lop

e o

f th

e

lin

e t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts.

1.

2.

( 1,

3)

( 0,

0)

x

y

O

y=

3x

3.

-

2; -

2

3;

3

3 −

2 ; 3

2

Su

pp

ose y

va

rie

s d

irectl

y a

s x

. W

rit

e a

dir

ect

va

ria

tio

n e

qu

ati

on

th

at

rela

tes x

to

y.

Th

en

so

lve.

4. If

y =

4 w

hen

x =

2,

fin

d y

wh

en x

= 1

6.

y =

2x;

32

5. If

y =

9 w

hen

x =

-3,

fin

d x

wh

en y

= 6

. y =

-3

x; -

2

6. If

y =

-4.8

wh

en x

= -

1.6

, fi

nd

x w

hen

y =

-24.

y =

3x; -

8

7. If

y =

1 −

4 w

hen

x =

1 −

8 ,

fin

d x

wh

en y

=

3 −

16 .

y =

2x;

3 −

32

( –2

, –

3)

( 0,

0)

x

y O

y=

3 2x

( –1

, 2)

( 0,

0)

x

y

O

y=

–2

x

( 2,

1)

( 0,

0)

x

y

Oy=

1 2x

Exam

ple

1Exam

ple

2

Lesson 3-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

25

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n (c

on

tin

ued

)

Dir

ect

Vari

ati

on

3-4

Dir

ect

Vari

ati

on

Pro

ble

ms

Th

e d

ista

nce f

orm

ula

d =

rt

is a

dir

ect

vari

ati

on

equ

ati

on.

In t

he

form

ula

, d

ista

nce

d v

ari

es d

irec

tly a

s ti

me

t, a

nd

th

e ra

te r

is

the

con

stan

t of

vari

ati

on.

TR

AV

EL A

fa

mil

y d

ro

ve t

heir

ca

r 2

25 m

iles i

n 5

ho

urs.

a.

Writ

e a

dir

ect

va

ria

tio

n e

qu

ati

on

to

fin

d t

he d

ista

nce t

ra

vele

d f

or a

ny

nu

mb

er

of

ho

urs.

Use

giv

en v

alu

es f

or d

an

d t

to

fin

d r

.

d

= r

t O

rigin

al equation

225 =

r(5

) d

= 2

25 a

nd t

= 5

45 =

r

Div

ide e

ach s

ide b

y 5

.

Th

eref

ore,

th

e d

irec

t vari

ati

on e

qu

ati

on i

s d

= 4

5t.

b.

Gra

ph

th

e e

qu

ati

on

.

Th

e gra

ph

of

d =

45

t p

ass

es t

hro

ugh

th

e or

igin

wit

hsl

ope

45.

m =

45 −

1

rise −

run

✔C

HE

CK

(5,

225)

lies

on

th

e gra

ph

.

c.

Esti

ma

te h

ow

ma

ny

ho

urs i

t w

ou

ld t

ak

e t

he

fam

ily

to

driv

e 3

60 m

iles.

d

= 4

5t

Origin

al equation

360 =

45

t R

epla

ce d

with 3

60.

t =

8

Div

ide e

ach s

ide b

y 4

5.

Th

eref

ore,

it

wil

l ta

ke

8 h

ours

to

dri

ve

360 m

iles

.

Exerc

ises

1. R

ET

AIL

Th

e to

tal

cost

C o

f bu

lk j

elly

bea

ns

is

$4.4

9 t

imes

th

e n

um

ber

of

pou

nd

s p

.

a.

Wri

te a

dir

ect

vari

ati

on e

qu

ati

on t

hat

rela

tes

the

vari

able

s.

C =

4.4

9p

b.

Gra

ph

th

e eq

uati

on o

n t

he

gri

d a

t th

e ri

gh

t.

c.

Fin

d t

he

cost

of

3 −

4 p

oun

d o

f je

lly b

ean

s. $

3.3

7

2. C

HE

MIS

TR

Y C

harl

es’s

Law

sta

tes

that,

at

a c

onst

an

t

pre

ssu

re,

vol

um

e of

a g

as

V v

ari

es d

irec

tly a

s it

s te

mp

eratu

re T

. A

vol

um

e of

4 c

ubic

fee

t of

a c

erta

in

gas

has

a t

emp

eratu

re o

f 200 d

egre

es K

elvin

.

a.

Wri

te a

dir

ect

vari

ati

on e

qu

ati

on t

hat

rela

tes

the

vari

able

s.

V

= 0

.02T

b.

Gra

ph

th

e eq

uati

on o

n t

he

gri

d a

t th

e ri

gh

t.

c.

Fin

d t

he

vol

um

e of

th

e sa

me

gas

at

250 d

egre

es K

elvin

. 5 f

t3Au

tom

ob

ile T

rip

s

Tim

e (

ho

urs

)

Distance (miles)

10

23

45

67

8t

d

360

270

180

90

( 1,

45)

( 5,

22

5)

d=

45

t

Co

st

of

Jell

y B

ean

s

Weig

ht

(po

un

ds)

Cost (dollars)

20

4w

C

18.00

13.50

9.00

4.50

Ch

arl

es’s

Law

Tem

pera

ture

(K

)

Volume (cubic feet)

100

0200

T

V 4 3 2 1

Exam

ple

Answers (Lesson 3-4)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A12 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

26

Gle

ncoe A

lgeb

ra 1

Sk

ills

Practi

ce

Dir

ect

Vari

ati

on

3-4

Na

me t

he c

on

sta

nt

of

va

ria

tio

n f

or e

ach

eq

ua

tio

n.

Th

en

dete

rm

ine t

he s

lop

e o

f th

e

lin

e t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts.

1.

( 3,

1)

( 0,

0)

x

y O

y=

1 3x

1

3 ; 1

3

2.

-2;

-2

3.

- 3

2 ;

Gra

ph

ea

ch

eq

ua

tio

n.

4. y =

3x

5. y =

- 3

4 x

6. y =

2

5 x

Su

pp

ose y

va

rie

s d

irectl

y a

s x

. W

rit

e a

dir

ect

va

ria

tio

n e

qu

ati

on

th

at

rela

tes

x a

nd

y.

Th

en

so

lve.

7. If

y =

-8 w

hen

x =

-2,

fin

d x

8. If

y =

45 w

hen

x =

15,

fin

d x

w

hen

y =

32.

y =

4x;

8

w

hen

y =

15.

y =

3x;

5

9. If

y =

-4 w

hen

x =

2,

fin

d y

10. If

y =

-9 w

hen

x =

3,

fin

d y

w

hen

x =

-6.

y =

-2

x;

12

w

hen

x =

-5.

y =

-3x;

15

11. If

y =

4 w

hen

x =

16,

fin

d y

12. If

y =

12 w

hen

x =

18,

fin

d x

w

hen

x =

6.

y =

1

4 x

; 3

2

w

hen

y =

-16.

y =

2

3 x

; -

24

Writ

e a

dir

ect

va

ria

tio

n e

qu

ati

on

th

at

rela

tes t

he v

aria

ble

s.

Th

en

gra

ph

th

e e

qu

ati

on

.

13. T

RA

VE

L T

he

tota

l co

st C

of

gaso

lin

e

14. S

HIP

PIN

G T

he

nu

mber

of

del

iver

ed t

oys

T

is $

3.0

0 t

imes

th

e n

um

ber

of

gall

ons

g.

is

3 t

imes

th

e to

tal

nu

mber

of

crate

s c.

Gaso

lin

e C

ost

Gallo

ns

Cost ($)

20

46

71

35

g

C

28

24

20

16

12 8 4

C =

3.0

0g

Toys S

hip

ped

Cra

tes

Toys

20

46

71

35

c

T

21

18

15

12 9 6 3

T

= 3

c

x

y

Ox

y

Ox

y

O

( –2

, 3)

( 0,

0)

x

y

O

y=–

3 2x

( -1

, 2

)( 0

, 0

)

x

y

O

y=-

2x

- 3

2

Lesson 3-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

27

Gle

ncoe A

lgeb

ra 1

Practi

ce

Dir

ect

Vari

ati

on

3-4

Na

me t

he c

on

sta

nt

of

va

ria

tio

n f

or e

ach

eq

ua

tio

n.

Th

en

dete

rm

ine t

he s

lop

e o

f th

e

lin

e t

ha

t p

asses t

hro

ug

h e

ach

pa

ir o

f p

oin

ts.

1.

2.

3.

Gra

ph

ea

ch

eq

ua

tio

n.

4. y =

-2

x

5. y =

6 −

5 x

6. y =

- 5

2 x

Su

pp

ose y

va

rie

s d

irectl

y a

s x

. W

rit

e a

dir

ect

va

ria

tio

n e

qu

ati

on

th

at

rela

tes

x a

nd

y.

Th

en

so

lve.

7. If

y =

7.5

wh

en x

= 0

.5,

fin

d y

wh

en x

= -

0.3

. y =

15

x; - 4

.5

8. If

y =

80 w

hen

x =

32,

fin

d x

wh

en y

= 1

00.

y =

2.5

x;

40

9. If

y =

3 −

4 w

hen

x =

24,

fin

d y

wh

en x

= 1

2.

y =

1 −

32 x

; 3

8

Writ

e a

dir

ect

va

ria

tio

n e

qu

ati

on

th

at

rela

tes t

he v

aria

ble

s.

Th

en

gra

ph

th

e

eq

ua

tio

n.

10. M

EA

SU

RE

Th

e w

idth

W o

f a

11. T

ICK

ET

S T

he

tota

l co

st C

of

tick

ets

isre

ctan

gle

is

two

thir

ds

of t

he

len

gth

".

$4.5

0 t

imes

th

e n

um

ber

of

tick

ets

t.

W

= 2

3 "

C =

4.5

0t

12. PR

OD

UC

E T

he

cost

of

ban

an

as

vari

es d

irec

tly w

ith

th

eir

wei

gh

t. M

igu

el b

ough

t

3 1

2 p

oun

ds

of b

an

an

as

for

$1.1

2.

Wri

te a

n e

qu

ati

on t

hat

rela

tes

the

cost

of

the

ban

an

as

to t

hei

r w

eigh

t. T

hen

fin

d t

he

cost

of

4 1

4 p

oun

ds

of b

an

an

as.

C =

0.3

2p

; $1.3

6

x

y

O

x

y

Ox

y

O

Co

st

of

Tic

kets

Tic

kets

Cost ($)

20

46

13

5t

C

25

20

15

10 5

Recta

ng

le D

imen

sio

ns

Len

gth

Width

40

812

26

10

"

W 10 8 6 4 2

( –2

, 5

)

( 0,

0)

x

y

O

y=-

5 2x

( 3,

4)

( 0,

0)

x

y O

y=

4 3x

( 4,

3)

( 0,

0)

x

y O

y=

3x

4

4

3 ; 4

3

5 −

2 ; -

5 −

2

3

4 ;

3 −

4

Answers (Lesson 3-4)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A13 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

28

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Dir

ect

Vari

ati

on

3-4

1. E

NG

INE

S T

he

engin

e of

a c

hain

saw

re

qu

ires

a m

ixtu

re o

f en

gin

e oi

l an

d

gaso

lin

e. A

ccor

din

g t

o th

e d

irec

tion

s, o

il

an

d g

aso

lin

e sh

ould

be

mix

ed a

s sh

own

in

th

e gra

ph

bel

ow.

Wh

at

is t

he

con

stan

t of

vari

ati

on f

or t

he

lin

e gra

ph

ed?

2.5

2. R

AC

ING

In

2007,

En

gli

sh d

river

Lew

is

Ham

ilto

n w

on t

he

Un

ited

Sta

tes

Gra

nd

P

rix a

t th

e In

dia

nap

olis

Mot

or

Sp

eed

way.

His

sp

eed

du

rin

g t

he

race

aver

aged

125.1

45 m

iles

per

hou

r. W

rite

a

dir

ect

vari

ati

on e

qu

ati

on f

or t

he

dis

tan

ce

d t

hat

Ham

ilto

n d

rove

in h

hou

rs a

t th

at

spee

d.

3. C

UR

RE

NC

Y T

he

exch

an

ge

rate

fro

m

U.S

. d

olla

rs t

o B

riti

sh p

oun

d s

terl

ing (£

) w

as

ap

pro

xim

ate

ly $

2.0

7 t

o £

1 i

n 2

007.

Wri

te a

nd

sol

ve

a d

irec

t vari

ati

on

equ

ati

on t

o d

eter

min

e h

ow m

an

y p

oun

ds

ster

lin

g y

ou w

ould

rec

eive

in e

xch

an

ge

for

$90 o

f U

.S.

curr

ency

.

4. S

ALA

RY

Hen

ry s

tart

ed a

new

job

in

w

hic

h h

e is

paid

$9.5

0 a

n h

our.

Wri

te

an

d s

olve

an

equ

ati

on t

o d

eter

min

e H

enry

’s g

ross

sala

ry f

or a

40-h

our

wor

k w

eek

.

5. S

ALE

S T

AX

Am

elia

rec

eived

a g

ift

card

to

a l

ocal

mu

sic

shop

for

her

bir

thd

ay.

Sh

e p

lan

s to

use

th

e gif

t ca

rd t

o bu

y

som

e n

ew C

Ds.

a.

Am

elia

ch

ose

3 C

Ds

that

each

cos

t $16.

Th

e sa

les

tax o

n t

he

thre

e C

Ds

is $

3.9

6.

Wri

te a

dir

ect

vari

ati

on

equ

ati

on r

elati

ng s

ale

s ta

x t

o th

e p

rice

.

b.

Gra

ph

th

e eq

uati

on y

ou w

rote

in

p

art

a.

c.

Wh

at

is t

he

sale

s ta

x r

ate

th

at

Am

elia

is

payin

g o

n t

he

CD

s?

Oil (fl oz)

34 2 159

10 8 7 6

Gaso

lin

e (

gal)

32

10

54

x

y

6

Pri

ce (

$)

30

20

10

50

40

90

80

70

100

P60

Sales Tax ($)

34 2 15T 8 7 6

d =

125.1

45

h

u =

1.7

9 b

; ab

ou

t £

50.2

8

p =

9.5

h;

$380

T =

0.0

825P

8.2

5%

Lesson 3-4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

29

Gle

ncoe A

lgeb

ra 1

En

ric

hm

en

t 3-4

nth

Po

wer

Vari

ati

on

An

equ

ati

on o

f th

e fo

rm y

= kxn,

wh

ere k

≠ 0

, d

escr

ibes

an

nth

pow

er v

ari

ati

on.

Th

e vari

able

n c

an

be

rep

lace

d b

y 2

to

ind

icate

th

e se

con

d p

ower

of x (

the

squ

are

of x)

or b

y 3

to

ind

icate

th

e th

ird

pow

er o

f x (

the

cube

of x

).

Ass

um

e th

at

the

wei

gh

t of

a p

erso

n o

f aver

age

bu

ild

vari

es d

irec

tly a

s th

e cu

be

of t

hat

per

son

’s h

eigh

t. T

he

equ

ati

on o

f vari

ati

on h

as

the

form

w =

kh

3.

Th

e w

eigh

t th

at

a p

erso

n’s

leg

s w

ill

sup

por

t is

pro

por

tion

al

to t

he

cros

s-se

ctio

nal

are

a o

f th

e le

g b

ones

. T

his

are

a v

ari

es d

irec

tly a

s th

e sq

uare

of

the

per

son

’s h

eigh

t. T

he

equ

ati

on o

f vari

ati

on h

as

the

form

s =

kh

2.

An

sw

er e

ach

qu

esti

on

.

1. F

or a

per

son

6 f

eet

tall

wh

o w

eigh

s 200 p

oun

ds,

fin

d a

valu

e fo

r k i

n t

he

equ

ati

on w

= kh

3.

k =

0.9

3

2. U

se y

our

an

swer

fro

m E

xer

cise

1 t

o p

red

ict

the

wei

gh

t of

a p

erso

n w

ho

is 5

fee

t ta

ll.

ab

ou

t 116 p

ou

nd

s

3. F

ind

th

e valu

e fo

r k

in

th

e eq

uati

on w

= kh

3 f

or a

baby w

ho

is 2

0 i

nch

es

lon

g a

nd

wei

gh

s 6 p

oun

ds.

k

= 1

.296 f

or

h =

5

3 f

t

4. H

ow d

oes

you

r an

swer

to

Exer

cise

3 d

emon

stra

te t

hat

a b

aby i

s si

gn

ific

an

tly f

att

er i

n p

rop

orti

on t

o it

s h

eigh

t th

an

an

ad

ult

?

k

has a

gre

ate

r valu

e.

5. F

or a

per

son

6 f

eet

tall

wh

o w

eigh

s 200 p

oun

ds,

fin

d a

valu

e fo

r k i

n t

he

equ

ati

on s

= kh

2.

k

= 5

.56

6. F

or a

baby w

ho

is 2

0 i

nch

es l

ong a

nd

wei

gh

s 6 p

oun

ds,

fin

d a

n “

infa

nt

valu

e” f

or k

in

th

e eq

uati

on s

= kh

2.

k

= 2

.16 f

or

h =

5

3 f

t

7. A

ccor

din

g t

o th

e ad

ult

equ

ati

on y

ou f

oun

d (

Exer

cise

1),

how

mu

ch

wou

ld a

n i

magin

ary

gia

nt

20 f

eet

tall

wei

gh

?

7440 p

ou

nd

s

8. A

ccor

din

g t

o th

e ad

ult

equ

ati

on f

or w

eigh

t su

pp

orte

d (

Exer

cise

5),

how

m

uch

wei

gh

t co

uld

a 2

0-f

oot

tall

gia

nt’

s le

gs

act

uall

y s

up

por

t?

o

nly

2224 p

ou

nd

s

9. W

hat

can

you

con

clu

de

from

Exer

cise

s 7 a

nd

8?

A

nsw

ers

will

vary

. F

or

exam

ple

, b

on

e s

tren

gth

lim

its t

he s

ize h

um

an

s

can

att

ain

.

Answers (Lesson 3-4)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A14 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

30

Gle

ncoe A

lgeb

ra 1

Reco

gn

ize A

rith

meti

c Seq

uen

ces

A s

eq

uen

ce

is

a s

et

of

nu

mbers

in

a s

peci

fic

ord

er.

If

the d

iffe

ren

ce b

etw

een

su

ccess

ive t

erm

s is

con

stan

t, t

hen

th

e s

equ

en

ce i

s ca

lled

an

a

rit

hm

eti

c s

eq

uen

ce

.

W

rit

e a

n e

qu

ati

on

fo

r

the n

th t

erm

of

the s

eq

uen

ce

12,

15,

18,

21,

. .

. .

In t

his

sequ

en

ce,

a1 i

s 12.

Fin

d t

he c

om

mon

d

iffe

ren

ce.

12

+ 3

+ 3

+ 3

15

18

21

Th

e c

om

mon

dif

fere

nce

is

3.

Use

th

e f

orm

ula

for

the n

th t

erm

to w

rite

an

equ

ati

on

.

a n =

a 1 +

(n

- 1

)d

Form

ula

for

the n

th t

erm

a n =

12

+ (

n -

1)3

a 1

= 1

2,

d =

3

a n =

12

+ 3

n -

3

Dis

trib

utive P

ropert

y

a n =

3n

+ 9

S

implif

y.

Th

e e

qu

ati

on

for

the n

th t

erm

is

a n =

3n

+ 9

.

Exerc

ises

Dete

rm

ine w

heth

er e

ach

seq

uen

ce i

s a

n a

rit

hm

eti

c s

eq

uen

ce.

Writ

e yes o

r no

.

Ex

pla

in.

1. 1,

5,

9,

13,

17,

. .

. 2. 8,

4,

0,

-4,

-8,

. .

. 3. 1,

3,

9,

27,

81,

. .

.

Fin

d t

he n

ex

t th

ree t

erm

s o

f ea

ch

arit

hm

eti

c s

eq

uen

ce.

4. 9,

13,

17,

21,

25,

. .

. 5. 4,

0,

-4,

-8,

-12,

. .

. 6. 29,

35,

41,

47,

. .

.

Writ

e a

n e

qu

ati

on

fo

r t

he n

th t

erm

of

ea

ch

arit

hm

eti

c s

eq

uen

ce.

Th

en

gra

ph

th

e

first

fiv

e t

erm

s o

f th

e s

eq

uen

ce.

7. 1,

3,

5,

7,

. .

. 8.

-1,

-4,

-7,

-1

0,

. .

. 9.

-4,

-9,

-1

4,

-1

9,

. .

.

D

ete

rm

ine w

heth

er t

he

seq

uen

ce 1

, 3,

5,

7,

9,

11,

. .

. is

an

arit

hm

eti

c s

eq

uen

ce.

Ju

sti

fy y

ou

r

an

sw

er.

If p

oss

ible

, fi

nd

th

e c

om

mon

dif

fere

nce

betw

een

th

e t

erm

s. S

ince

3 -

1 =

2,

5 -

3 =

2,

an

d s

o o

n,

the c

om

mon

d

iffe

ren

ce i

s 2.

Sin

ce t

he d

iffe

ren

ce b

etw

een

th

e t

erm

s of

1,

3,

5,

7,

9,

11,

. .

. is

con

stan

t, t

his

is

an

ari

thm

eti

c se

qu

en

ce.

3-5

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Ari

thm

eti

c S

eq

uen

ces a

s L

inear

Fu

ncti

on

s

Ari

thm

eti

c S

eq

uen

ce

a n

um

erical pattern

that

incre

ases o

r decre

ases a

t a c

onsta

nt

rate

or

valu

e c

alle

d t

he c

om

mo

n d

iffe

ren

ce

Term

s o

f an

Ari

thm

eti

c S

eq

uen

ce

If a

1 is t

he f

irst

term

of

an a

rith

metic s

equence w

ith c

om

mon

diffe

rence d

, th

en t

he s

equence is a

1,

a1 +

d,

a1 +

2d

, a

1 +

3d

, .

. .

.

nth

Term

of

an

Ari

thm

eti

c S

eq

uen

ce

an =

a1 +

(n

- 1

)d

Exam

ple

1Exam

ple

2

2

9,

33,

37

-16,

-20,

-24

53,

59,

65

y

es;

d =

4

yes;

d =

-4

no

; n

o c

om

mo

n

dif

fere

nce

a

n =

2n

- 1

a

n =

-3n

+ 2

a

n =

-5n

+ 1

Lesson 3-5

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

31

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n (c

on

tin

ued

)

Ari

thm

eti

c S

eq

uen

ces a

s L

inear

Fu

ncti

on

s

Ari

thm

eti

c Seq

uen

ces

an

d F

un

ctio

ns

An

arit

hm

eti

c s

eq

uen

ce

is

a l

inear

fun

ctio

n i

n w

hic

h n

is

the i

nd

ep

en

den

t vari

able

, a n i

s th

e d

ep

en

den

t vari

able

, an

d t

he

com

mon

dif

fere

nce

d i

s th

e s

lop

e.

Th

e f

orm

ula

can

be r

ew

ritt

en

as

the f

un

ctio

n

a n =

a 1 +

(n

-1)d

, w

here

n i

s a c

ou

nti

ng n

um

ber.

S

EA

TIN

G T

here a

re 2

0 s

ea

ts i

n t

he f

irst

ro

w o

f th

e b

alc

on

y o

f th

e

au

dit

oriu

m.

Th

ere a

re 2

2 s

ea

ts i

n t

he s

eco

nd

ro

w,

an

d 2

4 s

ea

ts i

n t

he t

hir

d r

ow

.

a

. W

rit

e a

fu

ncti

on

to

rep

resen

t

this

seq

uen

ce.

Th

e f

irst

term

a 1 i

s 20.

Fin

d t

he

com

mon

dif

fere

nce

.

20

+ 2

+ 2

22

24

T

he c

om

mon

dif

fere

nce

is

2.

a

n =

a 1 +

(n

- 1

)d

= 2

0 +

(n

- 1

)2

= 2

0 +

2n

- 2

= 1

8 +

2n

T

he f

un

ctio

n i

s a

n =

18 +

2n

.

b. G

ra

ph

th

e f

un

cti

on

.

Th

e r

ate

of

chan

ge i

s 2.

Mak

e a

table

an

d

plo

t p

oin

ts.

n a

n

120

222

324

426

n1

20

22

24

26

28

23

4

an

Exerc

ises

1. K

NIT

TIN

G S

ara

h l

earn

s to

kn

it f

rom

her

gra

nd

moth

er.

Tw

o d

ays

ago,

she m

easu

red

th

e l

en

gth

of

the s

carf

sh

e i

s k

nit

tin

g t

o b

e 1

3 i

nch

es.

Yest

erd

ay,

she m

easu

red

th

e

len

gth

of

the s

carf

to b

e 1

5.5

in

ches.

Tod

ay i

t m

easu

res

18 i

nch

es.

Wri

te a

fu

nct

ion

to r

ep

rese

nt

the a

rith

meti

c se

qu

en

ce.

2. R

EFR

ESH

MEN

TS

Y

ou

agre

e t

o p

ou

r w

ate

r in

to t

he c

up

s fo

r th

e

Boost

er

Clu

b a

t a f

ootb

all

gam

e.

Th

e p

itch

er

con

tain

s 64 o

un

ces

of

wate

r w

hen

you

begin

. A

fter

you

have f

ille

d 8

cu

ps,

th

e p

itch

er

is

em

pty

an

d m

ust

be r

efi

lled

.

a.

Wri

te a

fu

nct

ion

to r

ep

rese

nt

the a

rith

meti

c se

qu

en

ce.

an =

-8n

b.

Gra

ph

th

e f

un

ctio

n.

3-5

form

ula

for

the n

th term

a 1 =

20 a

nd d

= 2

Dis

trib

utive P

ropert

y

Sim

plif

y.

an

n1

82

46

816

32

48

64

24

40

56

72

35

7

Exam

ple

an =

13 +

2.5

n

Answers (Lesson 3-5)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A15 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

32

Gle

ncoe A

lgeb

ra 1

Sk

ills

Practi

ce

Ari

thm

eti

c S

eq

uen

ces a

s L

inear

Fu

ncti

on

s

Dete

rm

ine w

heth

er e

ach

seq

uen

ce i

s a

n a

rit

hm

eti

c s

eq

uen

ce.

Writ

e yes o

r no

.

Ex

pla

in.

1. 4,

7,

9,

12,

. .

. 2.

15,

13,

11,

9,

. .

.

3. 7,

10,

13,

16,

. .

. 4.

-6,

-5,

-3,

-1,

. .

.

5.

-5,

-3,

-1,

1,

. .

. 6.

-9,

-12,

-15,

-18,

. .

.

7. 10,

15,

25,

40,

. .

. n

o

8.

-1

0,

-5,

0,

5,

. .

. y

es;

5

Fin

d t

he n

ex

t th

ree t

erm

s o

f ea

ch

arit

hm

eti

c s

eq

uen

ce.

9. 3,

7,

11,

15,

. .

. 10. 22,

20,

18,

16,

. .

.

11.

-13,

-11,

-9,

-7 .

. .

12.

-2,

-5,

-8,

-11,

. .

.

13. 19,

24,

29,

34,

. .

. 14. 16,

7,

-2,

-11,

. .

.

15. 2.5

, 5,

7.5

, 10,

. .

. 12.5

, 15,

17.5

16. 3.1

, 4.1

, 5.1

, 6.1

, .

. .

7.1

, 8.1

, 9.1

Writ

e a

n e

qu

ati

on

fo

r t

he n

th t

erm

of

ea

ch

arit

hm

eti

c s

eq

uen

ce.

Th

en

gra

ph

th

e

first

fiv

e t

erm

s o

f th

e s

eq

uen

ce.

17. 7,

13,

19,

25,

. .

. 18. 30,

26,

22,

18,

. .

. 19.

-7,

-4,

-1,

2,

. .

.

20. V

IDEO

DO

WN

LO

AD

ING

Bri

an

is

dow

nlo

ad

ing e

pis

odes

of

his

favor

ite

TV

sh

ow t

o p

lay

on h

is p

erso

nal

med

ia d

evic

e. T

he

cost

to

dow

nlo

ad

1 e

pis

ode

is $

1.9

9.

Th

e co

st t

o d

own

load

2 e

pis

odes

is

$3.9

8.

Th

e co

st t

o d

own

load

3 e

pis

odes

is

$5.9

7.

Wri

te a

fu

nct

ion

to

rep

rese

nt

the

ari

thm

etic

seq

uen

ce.

a

n =

1.9

9n

n

an

24

6

4

-4

-8O

n

an

O2

46

30

20

10

n

an

O2

46

30

20

10

3-5

no

yes;

-2

yes;

3n

o

yes;

2yes;

-3

-5,

-3,

-1

-14,

-17,

-20

39,

44,

49

-20,

-29,

-38

a

n =

6n

+ 1

a

n =

-4

n +

34

a n =

3n

- 1

0

19,

23,

27

14,

12,

10

Lesson 3-5

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

33

Gle

ncoe A

lgeb

ra 1

Practi

ce

Ari

thm

eti

c S

eq

uen

ces a

s L

inear

Fu

ncti

on

s

Dete

rm

ine w

heth

er e

ach

seq

uen

ce i

s a

n a

rit

hm

eti

c s

eq

uen

ce.

Writ

e yes o

r no.

Ex

pla

in.

1. 21,

13,

5,

-3,

. .

. 2.

-5,

12,

29,

46,

. .

. 3.

-2.2

, -

1.1

, 0.1

, 1.3

, .

. .

4. 1,

4,

9,

16,

. .

.

5. 9,

16,

23,

30,

. .

.

6.

-1.2

, 0.6

, 1.8

, 3.0

, .

. .

Fin

d t

he n

ex

t th

ree t

erm

s o

f ea

ch

arit

hm

eti

c s

eq

uen

ce.

7. 82,

76,

70,

64,

. .

. 8.

-49,

-35,

-21,

-7,

. .

. 9. 3

4 ,

1

2 ,

1

4 ,

0,

. .

.

10.

-10,

-3,

4,

11 .

. .

11. 12,

10,

8,

6,

. .

. 12. 12,

7,

2,

-3,

. .

.

Writ

e a

n e

qu

ati

on

fo

r t

he n

th t

erm

of

ea

ch

arit

hm

eti

c s

eq

uen

ce.

Th

en

gra

ph

th

e

first

fiv

e t

erm

s o

f th

e s

eq

uen

ce.

13. 9,

13,

17,

21,

. .

. 14.

-5,

-2,

1,

4,

. .

. 15. 19,

31,

43,

55,

. .

.

16. B

AN

KIN

G C

hem

dep

osit

ed $

115.0

0 i

n a

savin

gs

acc

oun

t. E

ach

wee

k t

her

eaft

er,

he

dep

osit

s $35.0

0 i

nto

th

e acc

oun

t.

a.

Wri

te a

fu

nct

ion

to

rep

rese

nt

the

tota

l am

oun

t C

hem

has

dep

osit

ed f

or a

ny p

art

icu

lar

nu

mber

of

wee

ks

aft

er h

is i

nit

ial

dep

osit

.

b.

How

mu

ch h

as

Ch

em d

epos

ited

30 w

eek

s aft

er h

is i

nit

ial

dep

osit

?

17. S

TO

RE

DIS

PLA

YS

Tam

ika i

s st

ack

ing b

oxes

of

tiss

ue

for

a s

tore

dis

pla

y.

Each

row

of

tiss

ues

has

2 f

ewer

box

es t

han

th

e ro

w b

elow

. T

he

firs

t ro

w h

as

23 b

oxes

of

tiss

ues

.

a.

Wri

te a

fu

nct

ion

to

rep

rese

nt

the

ari

thm

etic

seq

uen

ce.

b.

How

man

y b

oxes

wil

l th

ere

be

in t

he

ten

th r

ow?

n

an

O60

40

20

24

6

n

an

24

6

8 4

-4O

n

an

O2

46

30

20

10

3-5

y

es;

d =

-8

yes;

d =

17

no

; n

o c

om

mo

n

dif

fere

nce

5

8,

52,

46

7,

21,

35

- 1

4 ,

- 1

2 ,

- 3

4

a

n =

4n

+ 5

a

n =

3n

- 8

a

n =

12n

+ 7

a n =

35n

+ 1

15

$1165

5

1

8,

25,

32

4,

2,

0

-8,

-13,

-18

a n =

-2

n +

25

n

o;

no

co

mm

on

y

es;

d =

17

no

; n

o c

om

mo

n

dif

fere

nce

d

iffe

ren

ce

Answers (Lesson 3-5)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A16 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

34

Gle

ncoe A

lgeb

ra 1

1.P

OS

TA

GE

In

2008,

the

pri

ce f

or f

irst

cl

ass

mail

was

rais

ed t

o 42 c

ents

for

th

e fi

rst

oun

ce a

nd

17 c

ents

for

each

ad

dit

ion

al

oun

ce.

Th

e ta

ble

bel

ow s

how

s th

e co

st f

or w

eigh

ts u

p t

o5

oun

ces.

So

urc

e:

United S

tate

s P

osta

l S

erv

cie

H

ow m

uch

did

a l

ette

r w

eigh

th

at

cost

$1.6

1 t

o se

nd

?

2. S

PO

RT

S W

an

da i

s th

e m

an

ager

for

th

e so

ccer

tea

m.

On

e of

her

du

ties

is

to h

an

d

out

cup

s of

wate

r at

pra

ctic

e. E

ach

cu

p o

f w

ate

r is

4 o

un

ces.

Sh

e beg

ins

pra

ctic

e w

ith

a 1

28-o

un

ce c

oole

r of

wate

r. H

ow

mu

ch w

ate

r is

rem

ain

ing a

fter

sh

e h

an

ds

out

the

14th

cu

p?

3. T

HE

AT

ER

A t

hea

ter

has

20 s

eats

in

th

e fi

rst

row

, 22 i

n t

he

seco

nd

row

, 24 i

n t

he

thir

d r

ow,

an

d s

o on

for

25 r

ows.

How

m

an

y s

eats

are

in

th

e la

st r

ow?

4.N

UM

BE

R T

HE

OR

Y O

ne

of t

he

mos

t fa

mou

s se

qu

ence

s in

math

emati

cs i

s th

e F

ibon

acc

i se

qu

ence

. It

is

nam

ed a

fter

L

eon

ard

o d

e P

isa (

1170–1250)

or F

iliu

s B

onacc

i, a

lias

Leo

nard

o F

ibon

acc

i. T

he

firs

t se

ver

al

nu

mber

s in

th

e F

ibon

acc

i se

qu

ence

are

:1,

1,

2,

3,

5,

8,

13,

21,

34,

55,

89,

. .

.D

oes

this

rep

rese

nt

an

ari

thm

etic

se

qu

ence

? W

hy o

r w

hy n

ot?

5. SA

VIN

GS

Inga’s

gra

nd

fath

er d

ecid

es t

o st

art

a f

un

d f

or h

er c

olle

ge

edu

cati

on.

He

mak

es a

n i

nit

ial

con

trib

uti

on o

f $3000

an

d e

ach

mon

th d

epos

its

an

ad

dit

ion

al

$500.

Aft

er o

ne

mon

th h

e w

ill

have

con

trib

ute

d $

3500.

a.

Wri

te a

n e

qu

ati

on f

or t

he

nth

ter

m o

f th

e se

qu

ence

.

b.

How

mu

ch m

oney

wil

l In

ga’s

gra

nd

fath

er h

ave

con

trib

ute

d a

fter

24 m

onth

s?

$15,0

00

Wo

rd P

rob

lem

Pra

ctic

eA

rith

meti

c S

eq

uen

ces a

s L

inear

Fu

ncti

on

s

3-5 W

eig

ht

(ou

nces)

12

34

5

Po

sta

ge

(cen

ts)

42

59

76

93

110

8 o

un

ces

72 o

un

ces

68 s

eats

No

, b

ecau

se t

he d

iffe

ren

ce

betw

een

term

s i

s n

ot

co

nsta

nt.

an =

3000

+ 5

00

n

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 3-5

Ch

ap

ter

3

35

Gle

ncoe A

lgeb

ra 1

Ari

thm

eti

c S

eri

es

An

ari

thm

etic

ser

ies

is a

ser

ies

in w

hic

h e

ach

ter

m a

fter

th

e fi

rst

may b

e fo

un

d b

y a

dd

ing t

he

sam

e n

um

ber

to

the

pre

ced

ing t

erm

. L

et S

sta

nd

for

th

e fo

llow

ing s

erie

s in

wh

ich

each

ter

m

is 3

mor

e th

an

th

e p

rece

din

g o

ne.

S =

2 +

5 +

8 +

11

+ 1

4 +

17

+ 2

0

Th

e se

ries

rem

ain

s th

e sa

me

if w

e

S =

2

+

5 +

8

+ 1

1 +

14

+ 1

7 +

20

rever

se t

he

ord

er o

f all

th

e te

rms.

So

S

= 2

0 +

17

+ 1

4 +

11

+

8 +

5

+

2

let

us

rever

se t

he

ord

er o

f th

e te

rms

2

S =

22

+ 2

2 +

22

+ 2

2 +

22

+ 2

2 +

22

an

d a

dd

on

e se

ries

to

the

oth

er,

term

2

S =

7(2

2)

by t

erm

. T

his

is

show

n a

t th

e ri

gh

t.

S =

7(2

2)

2

=

7(1

1)

= 7

7L

et a

rep

rese

nt

the

firs

t te

rm o

f th

e se

ries

.

Let

" r

epre

sen

t th

e la

st t

erm

of

the

seri

es.

Let

n r

epre

sen

t th

e n

um

ber

of

term

s in

th

e se

ries

.

In t

he

pre

ced

ing e

xam

ple

, a

= 2

, l

= 2

0,

an

d n

= 7

. N

otic

e th

at

wh

en y

ou a

dd

th

e tw

o se

ries

, te

rm b

y t

erm

, th

e su

m o

f ea

ch p

air

of

term

s is

22.

Th

at

sum

can

be

fou

nd

by a

dd

ing t

he

firs

t an

d l

ast

ter

ms,

2 +

20 o

r a

+ "

. N

otic

e als

o th

at

ther

e are

7,

or n

, su

ch s

um

s. T

her

efor

e, t

he

valu

e of

2S

is

7(2

2),

or

n(a

+ "

) in

th

e gen

eral

case

. S

ince

th

is i

s tw

ice

the

sum

of t

he

seri

es,

you

can

use

th

e fo

rmu

la

S =

n

(a +

")

2

to

fin

d t

he

sum

of

an

y a

rith

met

ic s

erie

s.

F

ind

th

e s

um

: 1

+ 2

+ 3

+ 4

+ 5

+ 6

+ 7

+ 8

+ 9

a =

1,

" =

9,

n =

9,

so S

= 9(1

+ 9

) −

2

= 9 .

10

2

= 4

5

F

ind

th

e s

um

: -

9 +

(-

5)

+ (

-1)

+ 3

+ 7

+ 1

1 +

15

a =

29,

" =

15,

n =

7,

so S

= 7(-

9 +

15)

2

= 7

. 6

2 =

21

Exerc

ises

Fin

d t

he s

um

of

ea

ch

arit

hm

eti

c s

erie

s.

1.

3 +

6 +

9 +

12

+ 1

5 +

18

+ 2

1 +

24

2. 10

+ 1

5 +

20

+ 2

5 +

30

+ 3

5 +

40

+ 4

5 +

50

3. -

21

+ (

-16)

+ (

-11)

+ (

-6)

+ (

-1)

+ 4

+ 9

+ 1

4

4. ev

en w

hol

e n

um

ber

s fr

om 2

th

rou

gh

100

5. od

d w

hol

e n

um

ber

s bet

wee

n 0

an

d 1

00

En

ric

hm

en

t 3-5

Exam

ple

1

Exam

ple

2

108

270

-28

2550

2500

Answers (Lesson 3-5)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A17 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

36

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n

Pro

po

rtio

nal

an

d N

on

pro

po

rtio

nal

Rela

tio

nsh

ips.

Pro

po

rtio

nal

Rela

tio

nsh

ips

If t

he r

ela

tion

ship

betw

een

th

e d

om

ain

an

d r

an

ge o

f a

rela

tion

is

lin

ear,

th

e r

ela

tion

ship

can

be d

esc

ribed

by a

lin

ear

equ

ati

on

. If

th

e e

qu

ati

on

p

ass

es

thro

ugh

(0,

0)

an

d i

s of

the f

orm

y =

kx,

then

th

e r

ela

tion

ship

is

pro

port

ion

al.

CO

MPA

CT D

ISC

S

Su

pp

ose y

ou

pu

rch

ased

a n

um

ber o

f p

ack

ag

es o

f

bla

nk

co

mp

act

dis

cs.

If e

ach

pa

ck

ag

e c

on

tain

s 3

co

mp

act

dis

cs,

yo

u c

ou

ld m

ak

e a

ch

art

to s

ho

w t

he r

ela

tio

nsh

ip b

etw

een

th

e n

um

ber o

f p

ack

ag

es o

f co

mp

act

dis

cs

an

d t

he n

um

ber o

f d

iscs p

urch

ased

. U

se x

fo

r t

he n

um

ber o

f p

ack

ag

es a

nd

y f

or t

he n

um

ber o

f co

mp

act

dis

cs.

Mak

e a

table

of

ord

ere

d p

air

s fo

r se

vera

l p

oin

ts o

f th

e g

rap

h.

Nu

mb

er

of

Packag

es

12

34

5

Nu

mb

er

of

CD

s3

69

12

15

Th

e d

iffe

ren

ce i

n t

he x

valu

es

is 1

, an

d t

he d

iffe

ren

ce i

n t

he y

valu

es

is 3

. T

his

patt

ern

sh

ow

s th

at

y i

s alw

ays

thre

e t

imes

x.

Th

is s

uggest

s th

e r

ela

tion

y =

3x.

Sin

ce t

he r

ela

tion

is

als

o a

fu

nct

ion

, w

e c

an

wri

te t

he e

qu

ati

on

in

fu

nct

ion

nota

tion

as

f(x)

= 3

x.

Th

e r

ela

tion

in

clu

des

the p

oin

t (0

, 0)

beca

use

if

you

bu

y 0

pack

ages

of

com

pact

dis

ks,

you

w

ill

not

have a

ny c

om

pact

dis

cs.

Th

ere

fore

, th

e r

ela

tion

ship

is

pro

port

ion

al.

Exerc

ises

1. N

AT

UR

AL G

AS

N

atu

ral

gas

use

is

oft

en

measu

red

in

“th

erm

s.”

Th

e t

ota

l am

ou

nt

a g

as

com

pan

y w

ill

charg

e f

or

natu

ral

gas

use

is

base

d o

n h

ow

mu

ch n

atu

ral

gas

a h

ou

seh

old

u

ses.

Th

e t

able

sh

ow

s th

e r

ela

tion

ship

betw

een

natu

ral

gas

use

an

d t

he t

ota

l co

st.

Gas U

sed

(th

erm

s)

12

34

To

tal

Co

st

($)

$1.3

0$2.6

0$3.9

0$5.2

0

a.

Gra

ph

th

e d

ata

. W

hat

can

you

ded

uce

fro

m t

he p

att

ern

abou

t th

e r

ela

tion

ship

betw

een

th

e n

um

ber

of

therm

s u

sed

an

d t

he t

ota

l co

st?

Th

e r

ela

tio

nsh

ip i

s p

rop

ort

ion

al.

b.

Wri

te a

n e

qu

ati

on

to d

esc

ribe t

his

rela

tion

ship

. y =

1.3

0x

c.

Use

th

is e

qu

ati

on

to p

red

ict

how

mu

ch i

t w

ill

cost

if

a h

ou

seh

old

u

ses

40 t

herm

s.

$52.0

0

3-6 Exam

ple

Total Cost ($)

23 1

0

456y

Gas

Use

d (

ther

ms)

32

1x

4

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 3-6

Ch

ap

ter

3

37

Gle

ncoe A

lgeb

ra 1

Stu

dy

Gu

ide a

nd

In

terv

en

tio

n (c

on

tin

ued

)

Pro

po

rtio

nal

an

d N

on

pro

po

rtio

nal

Rela

tio

nsh

ips

No

np

rop

ort

ion

al

Rela

tio

nsh

ips

If t

he r

ati

o o

f th

e v

alu

e o

f x t

o t

he v

alu

e o

f y i

s d

iffe

ren

t fo

r se

lect

ord

ere

d p

air

s on

th

e l

ine,

the e

qu

ati

on

is

non

pro

port

ion

al.

W

rit

e a

n e

qu

ati

on

in

fu

ncti

on

al

no

tati

on

fo

r t

he r

ela

tio

n s

ho

wn

in t

he g

ra

ph

.

Sele

ct p

oin

ts f

rom

th

e g

rap

h a

nd

pla

ce t

hem

in

a t

able

.

x

-1

01

23

y4

20

-2

-4

y

x

Th

e d

iffe

ren

ce b

etw

een

th

e x

–valu

es

is 1

, w

hil

e t

he

dif

fere

nce

betw

een

th

e y

-valu

es

is –

2.

Th

is s

uggest

s th

at

y =

–2

x.

If x

= 1

, th

en

y =

–2(1

) or

–2.

Bu

t th

e y

–valu

e f

or

x =

1 i

s 0.

x

1

2

3

-2

x-

2-

4-

6

y

0-

2-

4

y is a

lways 2

more

than -

2x

Th

is p

att

ern

sh

ow

s th

at

2 s

hou

ld b

e a

dd

ed

to o

ne s

ide o

f th

e e

qu

ati

on

. T

hu

s, t

he e

qu

ati

on

is

y =

-2

x +

2.

Exerc

ises

Writ

e a

n e

qu

ati

on

in

fu

ncti

on

no

tati

on

fo

r t

he r

ela

tio

n s

ho

wn

in

the t

ab

le.

Th

en

co

mp

lete

th

e t

ab

le.

1.

x-

10

12

34

y-

22

610

14

18

2

. x

-2

-1

01

23

y10

7

4 1

-2

-5

Writ

e a

n e

qu

ati

on

in

fu

ncti

on

no

tati

on

fo

r e

ach

rela

tio

n.

3.

x

y

O

4.

x

y O

3-6 Exam

ple

f(x

) =

4x

+ 2

f(x

) =

-3

x +

4

f(x

) =

-x

+ 2

f

(x)

= 2

x +

2

Answers (Lesson 3-6)

Co

pyrig

ht ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f Th

e M

cG

raw

-Hill C

om

pan

ies, In

c.

Chapter 3 A18 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

38

Gle

ncoe A

lgeb

ra 1

Sk

ills

Practi

ce

Pro

po

rtio

nal

an

d N

on

pro

po

rtio

nal

Rela

tio

nsh

ips

Writ

e a

n e

qu

ati

on

in

fu

ncti

on

no

tati

on

fo

r e

ach

rela

tio

n.

1.

2.

3.

4.

5.

6.

7.

GA

MESH

OW

S T

he t

able

sh

ow

s h

ow

man

y p

oin

ts a

re a

ward

ed

for

an

sweri

ng

con

secu

tive q

uest

ion

s on

a g

am

esh

ow

.

Qu

esti

on

an

sw

ere

d1

23

45

Po

ints

aw

ard

ed

200

400

600

800

1000

a

. W

rite

an

equ

ati

on

for

the d

ata

giv

en

. y =

20

0x

b

. F

ind

th

e n

um

ber

of

poin

ts a

ward

ed

if

9 q

uest

ion

s w

ere

an

swere

d.

1800

xO

f(x)

xO

f(x)

xO

f(x)

xO

f(x)

xO

f(x)

xO

f(x)

3-6

f

(x)

= -

2x

f(x

) =

x -

2

f

(x)

= 1

- x

f(x

) =

x +

6

f

(x)

= 5

- x

f(x

) =

2x

- 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 3-6

Ch

ap

ter

3

39

Gle

ncoe A

lgeb

ra 1

Practi

ce

Pro

po

rtio

nal

an

d N

on

pro

po

rtio

nal

Rela

tio

nsh

ips

1.B

IOLO

GY

M

ale

fir

efl

ies

flash

in

vari

ou

s p

att

ern

s to

sig

nal

loca

tion

an

d p

erh

ap

s to

ward

off

pre

dato

rs.

Dif

fere

nt

speci

es

of

fire

flie

s h

ave d

iffe

ren

t fl

ash

ch

ara

cteri

stic

s, s

uch

as

the

inte

nsi

ty o

f th

e f

lash

, it

s ra

te,

an

d i

ts s

hap

e.

Th

e t

able

belo

w s

how

s th

e r

ate

at

wh

ich

a

male

fir

efl

y i

s fl

ash

ing.

Tim

es (

seco

nd

s)

12

34

5

Nu

mb

er

of

Fla

sh

es

24

68

10

a.

Wri

te a

n e

qu

ati

on

in

fu

nct

ion

nota

tion

for

the r

ela

tion

.

b.

How

man

y t

imes

wil

l th

e f

irefl

y f

lash

in

20 s

eco

nd

s?

2. G

EO

ME

TR

Y T

he t

able

sh

ow

s th

e n

um

ber

of

dia

gon

als

that

can

be d

raw

n f

rom

on

e v

ert

ex i

n a

poly

gon

. W

rite

an

equ

ati

on

in

fu

nct

ion

nota

tion

for

the r

ela

tion

an

d

fin

d t

he n

um

ber

of

dia

gon

als

th

at

can

be d

raw

n f

rom

on

e v

ert

ex i

n a

12-s

ided

poly

gon

.

Writ

e a

n e

qu

ati

on

in

fu

ncti

on

no

tati

on

fo

r e

ach

rela

tio

n.

3.

4.

5.

Fo

r e

ach

arit

hm

eti

c s

eq

uen

ce,

dete

rm

ine t

he r

ela

ted

fu

ncti

on

. T

hen

dete

rm

ine

if t

he f

un

cti

on

is p

rop

orti

on

al

or n

on

prop

orti

on

al.

Ex

pla

in.

6. 1,

3,

5,

. .

. 7. 2,

7,

12,

. .

.8.

-3,

-6,

-9, .

. .

a(n

) =

2n

- 1

; a

(n)

= 5

n-

3;

a

(n)

=-

3n

;

n

on

pro

po

rtio

nal;

n

on

pro

po

rtio

nal;

p

rop

ort

ion

al;

n

ot

of

form

y=

kx

no

t o

f fo

rm y

=kx

of

form

y=

kx

x

y O

x

y

O

x

y

O

3-6

Sid

es

34

56

Dia

go

nals

01

23

f

(x)

= -

1

2 x

f

(x)

= 3

x -

6

f(x

) =

2x

+ 4

f(t)

= 2

t, w

here

t i

s t

he

40

f(s)

= s

- 3

, w

here

s i

s t

he n

um

ber

of

sid

es

tim

e i

n s

eco

nd

s a

nd

f(t

) is

th

e n

um

ber

of

flash

es

an

d f

(s)

is t

he n

um

ber

of

dia

go

nals

; 9

Answers (Lesson 3-6)

Answers

Co

pyri

gh

t ©

Gle

nco

e/M

cG

raw

-Hill, a

div

isio

n o

f T

he M

cG

raw

-Hill C

om

pan

ies,

Inc.

Chapter 3 A19 Glencoe Algebra 1

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Ch

ap

ter

3

40

Gle

ncoe A

lgeb

ra 1

Wo

rd

Pro

ble

m P

racti

ce

Pro

po

rtio

nal

an

d N

on

pro

po

rtio

nal

Rela

tio

nsh

ips

1.O

NLIN

E S

HO

PPIN

G R

icard

o is

bu

yin

g

com

pu

ter

cable

s fr

om a

n o

nli

ne

stor

e. I

f h

e bu

ys

4 c

able

s, t

he

tota

l co

st w

ill

be

$24.

If h

e bu

ys

5 c

able

s, t

he

tota

l co

st

wil

l be

$29.

If t

he

tota

l co

st c

an

be

rep

rese

nte

d b

y a

lin

ear

fun

ctio

n,

wil

l th

e fu

nct

ion

be

pro

port

ion

al

or

non

pro

port

ion

al?

Exp

lain

.

2. FO

OD

It

tak

es a

bou

t fo

ur

pou

nd

s of

gra

pes

to

pro

du

ce o

ne

pou

nd

of

rais

ins.

T

he

gra

ph

sh

ows

the

rela

tion

for

th

e n

um

ber

of

pou

nd

s of

gra

pes

nee

ded

, x,

to m

ak

e y p

oun

ds

of r

ais

ins.

Wri

te a

n

equ

ati

on i

n f

un

ctio

n n

otati

on f

or t

he

rela

tion

sh

own

.

3. P

AR

KIN

G P

alm

er T

own

ship

rec

entl

y

inst

all

ed p

ark

ing m

eter

s in

th

eir

mu

nic

ipal

lot.

Th

e co

st t

o p

ark

for

h

hou

rs i

s re

pre

sen

ted

by t

he

equ

ati

on

C =

0.2

5h

.

a

. M

ak

e a t

able

of

valu

es t

hat

rep

rese

nts

th

is r

elati

onsh

ip.

b

. D

escr

ibe

the

rela

tion

ship

bet

wee

n t

he

tim

e p

ark

ed a

nd

th

e co

st.

4.M

USIC

A m

easu

re o

f m

usi

c co

nta

ins

the

sam

e n

um

ber

of

bea

ts t

hro

ugh

out

the

son

g.

Th

e ta

ble

sh

ows

the

rela

tion

for

th

e n

um

ber

of

bea

ts c

oun

ted

aft

er a

cer

tain

n

um

ber

of

mea

sure

s h

ave

bee

n p

layed

in

th

e si

x-e

igh

t ti

me.

Wri

te a

n e

qu

ati

on t

o d

escr

ibe

this

rel

ati

onsh

ip.

So

urce:

Sheet

Music

USA

5. G

EO

METR

Y A

fra

ctal

is a

patt

ern

co

nta

inin

g p

art

s w

hic

h a

re i

den

tica

l to

th

e ov

erall

patt

ern

. T

he

foll

owin

g

geo

met

ric

patt

ern

is

a f

ract

al.

a.

Com

ple

te t

he

table

.

b.

Wh

at

are

th

e n

ext

thre

e n

um

ber

s in

th

e p

att

ern

?

c.

Wri

te a

n e

qu

ati

on i

n f

un

ctio

n n

otati

on

for

the

patt

ern

.

Po

un

ds

of

Gra

pes

21

04

3

f(

x)

x5

67

8

Pounds of Raisins

1.5

2.0

1.0

0.5

2.5

4.0

3.5

3.0

3-6

Measu

res

Pla

yed

(x)

12

34

56

To

tal N

um

ber

of

Beats

(y)

612

18

24

30

36

Term

x1

23

4

Nu

mb

er

of

Sm

aller

Tri

an

gle

s

y1

4

9

16

y

= 6

x

25,

36,

49

f(x)

= x

2

no

np

rop

ort

ion

al;

do

es n

ot

pass t

hro

ug

h (

0,

0)

f

(x)

= 0

.25x

It c

osts

25 c

en

ts f

or

each

h

ou

r yo

u p

ark

in

th

e l

ot.

Tim

eh

12

34

Co

st

C0.2

50.5

0.7

51.0

Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.

NA

ME

DA

TE

PE

RIO

D

Lesson 3-6

Ch

ap

ter

3

41

Gle

ncoe A

lgeb

ra 1

En

ric

hm

en

t

Taxic

ab

Gra

ph

sY

ou h

ave

use

d a

rec

tan

gu

lar

coor

din

ate

syst

em t

o gra

ph

x

y

O

y=

x-

1

y=

-2

equ

ati

ons

such

as

y =

x -

1 o

n a

coo

rdin

ate

pla

ne.

In

a

coor

din

ate

pla

ne,

th

e n

um

ber

s in

an

ord

ered

pair

(x,

y)

can

be

an

y t

wo

real

nu

mber

s.

A t

ax

ica

b p

lan

e i

s d

iffe

ren

t fr

om t

he

usu

al

coor

din

ate

pla

ne.

T

he

only

poi

nts

all

owed

are

th

ose

that

exis

t alo

ng t

he

hor

izon

tal

an

d v

erti

cal

gri

d l

ines

. Y

ou m

ay t

hin

k o

f th

e p

oin

ts

as

taxic

abs

that

mu

st s

tay o

n t

he

stre

ets.

Th

e ta

xic

ab g

rap

h s

how

s th

e eq

uati

ons

y =

-2 a

nd

y =

x -

1.

Not

ice

that

one

of t

he

gra

ph

s is

no

lon

ger

a s

traig

ht

lin

e. I

t is

n

ow a

col

lect

ion

of

sep

ara

te p

oin

ts.

Gra

ph

th

ese e

qu

ati

on

s o

n t

he t

ax

ica

b p

lan

e a

t th

e r

igh

t.

x

y

O

1.

1.

2.

2.

3.

3.

4.

4.

1. y

= x

+ 1

2. y

= -

2x

+ 3

3. y

= 2

.5

4. x

= -

4

Use y

ou

r g

ra

ph

s f

or t

hese p

ro

ble

ms.

5. W

hic

h o

f th

e eq

uati

ons

has

the

sam

e gra

ph

in

bot

h t

he

usu

al

coor

din

ate

pla

ne

an

d t

he

taxic

ab p

lan

e?

6. D

escr

ibe

the

form

of

equ

ati

ons

that

have

the

sam

e gra

ph

in

bot

h t

he

usu

al

coor

din

ate

pla

ne

an

d t

he

taxic

ab p

lan

e.

In t

he t

ax

ica

b p

lan

e,

dis

tan

ces a

re n

ot

mea

su

red

dia

go

na

lly

, b

ut

alo

ng

th

e s

treets

.

Writ

e t

he t

ax

i-d

ista

nce b

etw

een

ea

ch

pa

ir o

f p

oin

ts.

7. (0

, 0)

an

d (

5,

2)

8. (0

, 0)

an

d (

-3,

2)

9. (0

, 0)

an

d (

2,

1.5

)

10. (1

, 2)

an

d (

4,

3)

11. (2

, 4)

an

d (

-1,

3)

12. (0

, 4)

an

d (

-2,

0)

Dra

w t

hese g

ra

ph

s o

n t

he t

ax

ica

b g

rid

at

the r

igh

t.

13. T

he

set

of p

oin

ts w

hos

e ta

xi-

dis

tan

ce f

rom

(0,

0)

is 2

un

its.

14. T

he

set

of p

oin

ts w

hos

e ta

xi-

dis

tan

ce f

rom

(2,

1)

is 3

un

its.

x

y

O

3-6

x =

-4

x =

A a

nd

y =

B,

wh

ere

A a

nd

B a

re i

nte

gers

7 u

nit

s

5 u

nit

s

3.5

un

its

4 u

nit

s

4 u

nit

s

6 u

nit

s

ind

icate

d b

y X

ind

icate

d b

y d

ots

Answers (Lesson 3-6)

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