Lesson 6.1

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6-1 Integer Exponents

Warm Up

Lesson Presentation

Lesson Quiz

6-1 Integer Exponents

Warm Up

Evaluate each expression for the given values of the variables.

1. x 3 y 2 for x = –1 and y = 10

2.

for x = 4 and y = (–7)

Write each number as a power of the given base.

3. 64; base 4

4. –27; base (–3)

Holt McDougal Algebra 1

6-1 Integer Exponents

Objectives

Evaluate expressions containing zero and integer exponents.

Simplify expressions containing zero and integer exponents.

Holt McDougal Algebra 1

6-1 Integer Exponents

RECALL:

Positive exponents.

To simplify 3 2 , use 3 as a factor 2 times: 3 2 = ???

VOCABULARY

EXPONENT

Positive exponents

5 3

BASE

Holt McDougal Algebra 1

6-1 Integer Exponents

ZERO OR NEGATIVE EXPONENTS look for a pattern to figure it out.

5

Power

Value

5 5 5 4 5 3 5 2 5 1

3125 625 125 25 5

0 =

5

5

= 1

 5

5

 5  5  5

−1 =

1

5

1

=

5 1

5 0 5 –1 5 –2

5

When the exponent decreases by one, the value of the power is divided by 5.

−2 =

1

5

÷ 5 =

1

25

=

1

5 2

Holt McDougal Algebra 1

6-1 Integer Exponents

VOCABULARY

1. Zero Exponents – Any nonzero number raised to the zero power is 1.

Examples:

3 0 = 1

(−16) 0 = 1 𝑥 0 = 1

Holt McDougal Algebra 1

6-1 Integer Exponents

VOCABULARY

2. Negative Exponents– A nonzero number raised to a negative exponent is equal to 1 divided by that number raised to the opposite (postive) exponent.

Example:

3 −2 =

1

3 2

=

1

9

1 𝑥 −𝑛 = 𝑥 𝑛

Holt McDougal Algebra 1

2 −4 =

1

2 4

1

=

16

6-1 Integer Exponents

Why “nonzero number” in the previous definition?

0 0 = 0

0 −2 =

1

0 2

=

1

0

= 𝑢𝑛𝑑𝑒𝑓𝑖𝑛𝑒𝑑

Holt McDougal Algebra 1

6-1 Integer Exponents

Reading Math

2 –4 is read “2 to the negative fourth power.”

Holt McDougal Algebra 1

6-1 Integer Exponents

Example 1: Application

One cup is 2 –4 gallons. Simplify this expression.

gal is equal to

Holt McDougal Algebra 1

6-1 Integer Exponents

Try this one yourself!!!

A sand fly may have a wingspan up to 5 –3 m.

Simplify this expression.

Holt McDougal Algebra 1

6-1 Integer Exponents

TRY THESE YOURSELF!!!

Simplify.

A. 4 –3

B. 7 0

C. (–5) –4

7º = 1

D. –5 –4

E. (–2) –5

Holt McDougal Algebra 1

6-1 Integer Exponents

Caution

In (–5) –4 , the base is negative because the negative sign is inside the parentheses. In –5 –4 the base (5) is positive.

Holt McDougal Algebra 1

6-1 Integer Exponents

Example 2

Evaluate the expression for the given value of the variables.

x –2 for x = 4

Substitute 4 for x.

Use the definition

Holt McDougal Algebra 1

6-1 Integer Exponents

Example 3: Try another yourself!!!

Simplify the expression for the given values of the variables.

–2a 0 b -4 for a = 5 and b = –3

Substitute 5 for a and –3 for b.

Evaluate expressions with exponents.

Write the power in the denominator as a product.

Simplify the denominator.

Simplify.

Holt McDougal Algebra 1

6-1 Integer Exponents

Try these yourself!!!

Evaluate the expression for the given value of the variable.

1.) p –3 for p = 4

2.) for a = –2 and b = 6

Holt McDougal Algebra 1

6-1 Integer Exponents

What if you have an expression with a negative exponent in a denominator, such as ?

1 𝑥 −𝑛

= 𝑥 𝑛

*Move the denominator to the top and change the sign

**An answer with a negative exponent

IS NOT simplified fully

Holt McDougal Algebra 1

6-1 Integer Exponents

Example 4: Together

Simplify.

A. 7w –4 B.

Holt McDougal Algebra 1

6-1 Integer Exponents

Example 4: Simplifying Expressions with Zero and

Negative Numbers

Simplify.

C.

and

Holt McDougal Algebra 1

6-1 Integer Exponents

PRACTICE: ON YOUR OWN

Simplify.

a. 2r 0 m –3 b.

c.

Holt McDougal Algebra 1

6-1 Integer Exponents

6.1 HOMEWORK

PG. 395 - 397

#24-42(all), 44-66(evens),

78-83, 100

Holt McDougal Algebra 1

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