Transcript Introduction to Exponents and Powers

OBJECTIVE
I will express and evaluate
numbers using powers.
Powers
A power is a number represented by a base and
an exponent. The exponent tells you how
many times to use the base as a repeated
factor.
Exponent
2
Base
Common Powers
1. 101 (ten to the first power) = 10
2. 32 (three to the second power, three
squared) = 3 • 3 = 9
3. 43 (four to the third power, four cubed)
= 4 • 4 • 4 = 64
4. xn (x to the nth power)
Guided Practice
Evaluate the expression x4 when x = 3.
Step 1: x4
Expression
Step 2: 34
Substitute
Step 3: 3 • 3 • 3 • 3 Write factors
Step 4: 81
Multiply
Evaluating Exponents with
Grouping Symbols
•
Grouping Symbols - tell what operation to
perform first (i.e. parentheses, brackets)
Evaluate when x = 5.
(a) 3x2
(b) (3x)2
= 3 • 52
= (3 • 5)2
=3•5•5
= 152
= 75
= 15 • 15
= 225
Independent Practice
Evaluate the expression for when x = 10
1. x4
2. 2x3
3. (3x)2