Coordinate AlgebraPractice

EOCT AnswersUnit 1

#1 Unit 1A rectangle has a length of 12 m and a width of 400 cm. What is the perimeterof the rectangle?

Step 1: Change 12 meters to centimeters

× 100 cm 1 m

= 1200 cm12 m1

Step 2: Find perimeter using formula P = 2L + 2W

400 cm

1200 cm P = 2(1200 cm) + 2(400 cm)

P = 2400 cm + 800 cm

P = 3200 cm

A. 824 cm

B. 1600 cm

C. 2000 cm

D. 3200 cm

#2 Unit 1

The tension caused by a wave moving along a string is found

using the formula T = . If m is the mass of the string in

grams, L is the length of the string in centimeters, and v is the velocity of the wave in centimeters per second, what is the unit of the tension of the string, T ?

2mv

L

2 22

2

( )

( )

sec (sec)

( )

m grams g

cm cmv

L cm

2mvT

L

2

2

( )( )

(sec)( )

cmg

cm

#2 Unit 1

(cm)

1

2

2

( )( )

(sec)( )

cmg

Tcm

2

2

( )(sec)( )

g cm

cm

2

2

( ) ( )

(sec) 1

g cm cm

2

2 1

( ) 1

(sec) ( )

g cmT

cm

1

2

( ) 1

(sec) 1

g cm 2

( )

(sec)

g cm

A. gram-centimeters per second squaredB. centimeters per second squaredC. grams per centimeter-second squaredD. centimeters squared per second

#3 Unit 1

The distance a car travels can be found using the formula d = rt, where d is the distance, r is the rateof speed, and t is time. How many miles does the car travel, if it drives at a speed of 70 miles per hour for ½ hour?

d = r t1

270 miles hour

hour 1d

70 miles 0.5 hour

hour 1d = 35 miles

A. 35 miles

B. 70 miles

C. 105 miles

D. 140 miles

#4

Unit 1 A certain population of bacteria has an average growth rate of 0.02 bacteria per hour. The formula for the growth of the bacteria’s population is A= P (2.71828)0.02t, where P0 is the original population, and t is the time in hours.

If you begin with 200 bacteria, about how many bacteria will there be after 100 hours?

A= 200(2.71828)0.02100

A= 200(2.71828)2

A= 200(7.389046)

A= P(2.71828)0.02t

= 1477.81

Answer

1478

#5 Unit 1

The sum of the angle measures in a triangle is 180°. Two angles of a triangle measure 20° and 50°. What is the measure of the third angle?

Third Angle = x

x + 20° + 50° = 180°

x + 70° = 180°–70° –70°

x = 110°

A. 30°B. 70°C. 110°D. 160°

#6 Unit 1Which equation shows P = 2l + 2w when solved for w ?

–2l –2lP = 2l + 2w

P – 2l = 2w

P – 2l 2w 2 2

P – 2l2

=

= w

A.

B.

C.

D.

P

lw

2

2

2 Plw

22

Plw

2

2lPw

#7 Bruce owns a business that produces widgets. He must bring in more in revenue than he paysout in costs in order to turn a profit.

It costs $10 in labor and materials to make each of his widgets. His rent each month for his factory is $4000. He sells each widget for $25.

How many widgets does Bruce need to sell monthly to make a profit?

A. 160B. 260C. 267D. 400

C = 10x + 4000R = 25x

Cost to make x widgetsRevenue (in dollars)from selling x widgets

Unit 1

Note: A profit occurs when enough widgets are made and sold to break even. (i.e. R = C)

R = C25x = 10x + 4000(Set up equation)

#7 Bruce owns a business that produces widgets. He must bring in more in revenue than he paysout in costs in order to turn a profit.

It costs $10 in labor and materials to make each of his widgets. His rent each month for his factory is $4000. He sells each widget for $25.

How many widgets does Bruce need to sell monthly to make a profit?

A. 160B. 260C. 267D. 400

Unit 1

25x = 10x + 4000(Set up equation)

–10x –10x

15x = 4000

15x 400015 15=

x = 267

Note: A minimum of 267 widgets must be sold in order to make a profit.