Simplify (7p5)3.

Power RulesPower RulesCOURSE 3 LESSON 7-4COURSE 3 LESSON 7-4

(7p5)3 = 73(p5)3 Raise each factor to the third power.

= 73p15 = 343p15 Multiply the exponents. Simplify.

7-4

Use the formula for the area of a circle, A = r2, to find the

area of a circle with a radius of 4 10–2 m. Write the answer in

scientific notation. Use 3.14 for the value of .

Power RulesPower RulesCOURSE 3 LESSON 7-4COURSE 3 LESSON 7-4

The area of the circle is about 5.024 10–3 m2.

A = r2

= 3.14 • (4 10–2)2 Substitute 4 10–2 for r.

= 3.14 • 16 10–4 Raise 10–2 to the second power.

= 50.24 10–4 Multiply 3.14 and 16.

= 5.024 10–3 Write in scientific notation.

= 3.14 • 42 (10–2)2 Raise the product to a power.

7-4

Power RulesPower RulesCOURSE 3 LESSON 7-4COURSE 3 LESSON 7-4

1. Write (9–3)8 using a single exponent.

2. Simplify (2a6)3.

3. Find the area of a circle whose radius is 5 10–7 m. Use 3.14 for .

9–24

8a18

7.85 10–13 m2

7-4