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6.1 Properties of Exponents
2/4/2013
Power, Base and Exponent:
73
Exponent: is the number that tells you how many times the base is multiplied to itself.
In this example 73 means 7•7•7
Product of Powers:
Ex. 32 • 35
= 3•3•3•3•3•3•3 = 37
= 32+5
In general: am•an = am+n
Power of a Power:
Ex. (23 )2
= (23 )• (23 )=(2•2•2)•(2•2•2)= 26 = 23•2
In general: (am)n = am•n
Power of a Product:
Ex. (4•3 )3
= (4•3 )• (4•3 ) • (4•3 ) =(4•4•4)•(3•3•3) = 4 3 •3 3
In general: (a •b)m =a
m•b m
Zero Exponent
In general: a0 = 1
44 164 644 123
55 255 1255 123
33 93 273 123
÷5 ÷5 ÷5
÷4 ÷4 ÷4
÷3÷3 ÷3
Any base raised to a 0 power equals 1.
50 = 1
40 = 1
30 = 1
3
Exponential Form Fraction Form
33 27
32 9
31 3
30 1
3-1
3-2 =
3-3 =
Negative Exponent
Ex. 5-2
Ex.
In general:
25
1
mm
aa
1
Negative exponent MOVES power. If the power with a negative exponent is in the numerator, the power moves to the denominator and exponent becomes positive. If the power with a negative exponent is in the denominator, the power moves to the numerator and exponent becomes positive.
33
22
xx
Quotient of Powers
Ex.
In general:
33
33333
3
32
5
nmn
m
aa
a
253 33
Power of a Quotient
Ex.
In general:
4
44
5
3
5
3
5
3
5
3
5
3
5
3
m
mm
b
a
b
a
Example 1 Evaluate Expressions with Negative Exponents
( ) 82 – – ( )42– Product of powers property= ( ) 8 42 – – +
= ( ) 42 – – Simplify exponent.
1
( )42–= Negative exponent property
=161
Evaluate power.
Example 2 Evaluate Quotients with Exponents
33
35 2
Evaluate .
Quotient of powers property 33
35 2
= ( )232
= 34 Power of a power property
= 81 Evaluate power.
Checkpoint Evaluate Numerical Expressions
( )3221.
Evaluate the expression.
ANSWER 64
( )3502. ANSWER 1
3. ( ) 53 – –( )23– ANSWER271–
ANSWER278
4.3
2 3
Example 3 Simplify Algebraic Expressions
a.y
x– 3
2
Power of a quotient propertyx 2
( )2y – 3 =
=x 2
y – 3 2 •Power of a power property
=x 2
y – 6 Simplify exponent.
= x 2y 6 Negative exponent property
Example 3 Simplify Algebraic Expressions
= 25y y 5y – 6
Simplify exponent.
= 25y – 6 5 1 + + Product of powers property
= 25y 0 Simplify exponent.
= 25 Zero exponent property
( )25y – 3 y 5y b. = ( )2y – 3 y 5y 52 Power of a product property
= 25y y 5y – 3 2 • Power of a power property
Example 3 Simplify Algebraic Expressions
c.x 5y 2–
x 3y 6
= x – 3 5 y – 6 ( 2) – Quotient of powers property
= x 2y 8– Simplify exponent.
=y 8
x 2Negative exponent property
Checkpoint Simplify Algebraic Expressions
( )32p p 45.8p 7
6.xy 4–
x 5y 3x 4y 7
Simplify the expression.
7. ( )33b – 2 b 8 27b 2
–
s
r 2
– 4
3
8.1
r 6s 12
ANSWER
Homework:
6.1 p.299 #8-34 evenDisregard direction that
says. “Tell which properties you used”