NAME 9-1 DATE PERIOD Study Guide and Intervention Powers and Exponents Use Exponents A number that is expressed using an exponent is called a power. The base is the number that is multiplied. The exponent tells how many times the base is used as a factor. So, 43 has a base of 4 and an exponent of 3, and 43 = 4 · 4 · 4 = 64. 43 exponent { base Lesson 9-1 power Any number, except 0, raised to the zero power is defined to be 1. 10 = 1 Example 20 = 1 30 = 1 40 = 1 x0 = 1, x ≠ 0 50 = 1 Write each expression using exponents. a. 10 · 10 · 10 · 10 · 10 The base is 10. It is a factor 5 times, so the exponent is 5. 10 · 10 · 10 · 10 · 10 = 105 b. (–9) · (–9) · (–9) · (–9) · (–9) · (–9) The base is –9. It is a factor 6 times, so the exponent is 6. (–9) · (–9) · (–9) · (–9) · (–9) · (–9) = (–9)6 c. ( p + 2)( p + 2)(p + 2) The base is p + 2. It is a factor 3 times, so the exponent is 3. ( p + 2)( p + 2)( p + 2) = ( p + 2)3 Exercises Write each expression using exponents. 1. 5 · 5 · 5 · 5 · 5 · 5 · 5 2. (–7)(–7)(–7) 3. 4 · 4 4. 8 · 8 · 8 5. (–2) · (–2) · (–2) · (–2) 6. (3) ∙ (3) ∙ (3) ∙ (3) ∙ (3) 7. (0.4) · (0.4) · (0.4) 8. d · d · d · d 9. m · m · m · m · m · m · m 10. x · x · y · y Chapter 9 11. (z – 4)(z – 4) 5 1 1 1 1 1 12. 3(–t)(–t)(–t) Glencoe Pre-Algebra NAME DATE 9-1 PERIOD Study Guide and Intervention (continued) Powers and Exponents Evaluate Expressions When evaluating expressions with exponents you must follow the order of operations. Order of Operations 1. Simplify expressions inside grouping symbols. 2. Evaluate all powers. 3. Multiply and divide in order from left to right. 4. Add and subtract in order from left to right. Example 1 ART An artist is painting a mural that will look like a quilt square. The mural will have an area of 82 square feet. How many square feet is this? 8 is a factor 2 times. 82 = 8 · 8 Simplify. = 64 The area of the mural will be 64 square feet. Example 2 Evaluate x2 – 4 if x = –6. x2 – 4 = ( –6)2 – 4 Replace x with –6. = ( –6)( –6) – 4 –6 is a factor 2 times. = 36 – 4 Multiply. = 32 Subtract. Exercises Evaluate each expression. 1. 73 2. 36 5. (–4)5 9. 72 · 5 6. 28 10. 42 · 52 1 4 3. (–6)3 4. (5) 7. 33 · 6 8. 83 · 9 11. (–3)2 · (–2)3 12. 82 · 63 Evaluate each expression if g = 3, h = –1, and m = 9. 13. g 5 14. 5g2 15. g2 – m 16. hm2 17. g3 + 2h 18. m + h g3 19. 4(2m – 3)2 20. –2(g3 + 1) 21. 5(h4 – m2) Chapter 9 6 Glencoe Pre-Algebra