Powers and Exponents
Lesson #2
Pg. 175
What You’ll Learn
• Power
– Numbers using an exponent and base
• Base
– The common factor in a power
• Exponent
– The number of times the base is used as
a factor
•
https://www.youtube.com/watch?v=wCFSy_JKz3g
Write and Evaluate Powers
• A product of repeated factors can be
expressed as a power, that is, using an
exponent and a base.
44
factors
64444
7 444448
4
2 g2 g2 g2 2
The base is the common factor
The exponent tells how many times the
base is used as a factor
Read and Write Powers
Read and Write Powers
Power
1
3
2
3
3
3
4
3
Words
Factors
3 to the first power
3
3g3
3 to the second power or 3 squared
3 to the third power or 3 cubed
3 to the forth power or 3 to the forth
M
M
n
3 to the nth power or 3 to the nth
3
3g3g3
3g3g3g3
M
3144442
g3g3g L
g3
44443
n factors
Negatives Raised to Exponents
• (-) Raised to Even Exponents
– Will be positive (+)
• (-) Raised to Odd Exponents
– Will be negative (-)
• Watch for Parentheses
(-3)2
-32
-(3)2
Examples
• Write each expression using exponents
#1.
 2  g  2  g  2 
# 2. a g b g b g a g b
g3 g3 g3 g3
Evaluate Examples
 2
 
 3
4
 2 
5
1
 
5
3
• The deck of a skateboard has an area of about
25 • 7 in2.
What is the area of the skateboard deck?
Substitution Examples
• Evaluate each expression if
a = 3 and b = 5
a 2  b4
a  b
2
Substitution
• Evaluate if c = - 4 and d = 9
c d
3
2
d 3   c2  2
c  d 
3
HOMEWORK
HC: pg. 179-180
(1-16)
CC: pg. 179-180
(1-14, 16)
www.ixl.com 8th D1