Learn to evaluate expressions with exponents. Intro to Exponents Learn to evaluate expressions with exponents.
Review Find the product. 1. 5 • 5 • 5 • 5 625 2. 3 • 3 • 3 27 3. (–7) • (–7) • (–7) –343 4. 9 • 9 81
The term 27 is called a power The term 27 is called a power. If a number is in exponential form, the exponent represents how many times the base is to be used as a factor. Exponent Base 2 7
Write in exponential form. Identify how many times 4 is a factor. 4 • 4 • 4 • 4 = 44 B. d • d • d • d • d Identify how many times d is a factor. d • d • d • d • d = d5 Read 44 as “4 to the 4th power.” Reading Math
Write in exponential form. Identify how many times –6 is a factor. C. (–6) • (–6) • (–6) (–6) • (–6) • (–6) = (–6)3 Remember to keep the – sign inside the ( )! If it is outside, your answer will be negative even if you have an even number of – signs. D. 5 • 5 5 • 5 = 52 Identify how many times 5 is a factor.
Write in exponential form. A. x • x • x • x • x Identify how many times x is a factor. x • x • x • x • x = x5 B. d • d • d Identify how many times d is a factor. d • d • d = d3
Evaluate. Find the product of five 3’s. A. 35 35 = 3 • 3 • 3 • 3 • 3 = 243 B. (–3)5 Find the product of five –3’s. = (–3) • (–3) • (–3) • (–3) • (–3) (–3)5 = –243 Helpful Hint Always use parentheses to raise a negative number to a power.
Evaluate. Find the product of four 7’s. C. 74 74 = 7 • 7 • 7 • 7 = 2401 D. (–9)3 Find the product of three –9’s. = (–9) • (–9) • (–9) (–9)3 = –729
Simplifying Expressions Containing Powers Simplify (25 – 32 ) + 6(4) = (32 – 9) + 6(4) Evaluate the exponents. = (23) + 6(4) Subtract inside the parentheses. = 23 + 24 Multiply from left to right. = 47 Add from left to right.
Simplify (32 – 82) + 2 • 3 = (9 – 64) + 2 • 3 = (–55) + 2 • 3 Evaluate the exponents. = (–55) + 2 • 3 Subtract inside the parentheses. = –55 + 6 Multiply from left to right. = –49 Add from left to right.