4-1 The Distributive Property MENTAL MATH Find each product mentally. Justify your answer. 31. 8 • 22 SOLUTION: 32. 13 • 39 SOLUTION: 33. 19 • 41 SOLUTION: 34. 29 • 13 SOLUTION: 35. 75 • 40 SOLUTION: 36. 95 • 38 SOLUTION: eSolutions Manual - Powered by Cognero 37. 9 • 49 SOLUTION: Page 1 4-1 The Distributive Property 36. 95 • 38 SOLUTION: 37. 9 • 49 SOLUTION: 38. 31 • 11 SOLUTION: 39. 121 • 15 SOLUTION: 40. MONEY Sarah charges $6.50 per hour to babysit. She babysat for 3 hours on Friday, and 5 hours on Saturday. Write two equivalent expressions for her total wages. Then find her total wage. SOLUTION: To find her total wages, multiply her hourly rate by the total number of hours she babysat. Her total wages can be expressed as $6.50(3 + 5) or $6.50(3) + $6.50(5). Sarah made a total of $52.00 babysitting. 41. ENTERTAINMENT Admission to the state fair is $8 for adults and $7 for students. Write two equivalent expressions if two adults and two students go to the fair. Then find the total admission cost. SOLUTION: The total admission cost for two students and two adults can be expressed as 2($8 + $7) or 2($8) + 2($7). eSolutions Manual - Powered by Cognero The fair admission will cost $30 for two adults and two students. Page 2 4-1 The Distributive Property Sarah made a total of $52.00 babysitting. 41. ENTERTAINMENT Admission to the state fair is $8 for adults and $7 for students. Write two equivalent expressions if two adults and two students go to the fair. Then find the total admission cost. SOLUTION: The total admission cost for two students and two adults can be expressed as 2($8 + $7) or 2($8) + 2($7). The fair admission will cost $30 for two adults and two students. Use the Distributive Property to write each expression as an equivalent expression. Then evaluate the expression. (Hint: can be written as a sum of 3 + .) 43. SOLUTION: 44. SOLUTION: 45. SOLUTION: eSolutions Manual - Powered by Cognero Page 3 4-1 The Distributive Property 45. SOLUTION: 46. SOLUTION: 47. COSTUMES Aiko uses yards of fabric to make costumes for a play. Use the Distributive Property to find how much fabric she will need if she makes 9 costumes. SOLUTION: To make 9 costumes, Aiko will need 21 yards of fabric. Use the Distributive Property to write each expression as an equivalent algebraic expression. 48. 3(a + b) SOLUTION: eSolutions Manual - Powered by Cognero Page 4 4-1 The Distributive Property To make 9 costumes, Aiko will need 21 yards of fabric. Use the Distributive Property to write each expression as an equivalent algebraic expression. 48. 3(a + b) SOLUTION: 49. (e + f )(–5) SOLUTION: 50. –6(x – y) SOLUTION: 51. −4( j – k) SOLUTION: 52. 10(r – s) SOLUTION: 53. (u – w)(8) SOLUTION: 56. ERROR ANALYSIS Julia and Catelyn are using the Distributive Property to simplify 3(x + 2). Is either of them correct? Explain your reasoning. eSolutions Manual - Powered by Cognero SOLUTION: Page 5 4-1 The Distributive Property 56. ERROR ANALYSIS Julia and Catelyn are using the Distributive Property to simplify 3(x + 2). Is either of them correct? Explain your reasoning. SOLUTION: Catelyn is correct because each number inside the parentheses should be multiplied by 3. 57. CHALLENGE Is 3 + (x • y) = (3 + x) • (3 + y) a true statement? If so, explain your reasoning. If not, give a counterexample. SOLUTION: 3 + (x • y) ? (3 + x) • (3 + y) Substitute 4 for x and 5 for y, then evaluate to determine if the two expressions are equal. No, 3 + (x • y) is not equal to (3 + x) • (3 + y). 58. WRITING IN MATH Explain how you can use the Distributive Property and mental math to simplify . SOLUTION: Sample answer: You can break up 2(4 + )+ (4 + to be 2 + ). Distribute 2 • 4 + 2 • + and • 4 + to be 4 + • . Then set up the multiplication expression . Add 8 + 1 + 2 + = . Find each sum or difference. Write in simplest form. 63. SOLUTION: 64. SOLUTION: eSolutions Manual - Powered by Cognero Page 6 4-1 The Distributive Property 64. SOLUTION: 65. SOLUTION: 66. SOLUTION: 67. SEWING Jessica needs yards of fabric to make a skirt and yards to make a coat. How much fabric does she need in all? SOLUTION: eSolutions Manual - Powered by Cognero Page 7 4-1 The Distributive Property 67. SEWING Jessica needs yards of fabric to make a skirt and yards to make a coat. How much fabric does she need in all? SOLUTION: Jessica needs yards of fabric. Write each subtraction expression as an addition expression. 73. 9 – 12 SOLUTION: 9 – 12 = 9 + –12 74. –2 – 6 SOLUTION: –2 – 6 = –2 + –6 75. –10 – (–3) SOLUTION: –10 – (–3) = –10 + 3 76. –12 – 14 SOLUTION: –12 – 14 = –12 + –14 eSolutions Manual - Powered by Cognero Page 8