Error Analysis Describe and correct the error in each solution.

C Challenge

55. Geometry The base of a triangle is 12 in. Its height is (x + 6) in. Its area is no more than 72  in. 2 . 72 , in. squared , .  What are the possible integer values of x?
56. Part-Time Jobs You can earn money by tutoring for $8 per hour and by walking dogs for $7.50 per hour. You have 15 h available to work. What is the greatest number of hours you can spend walking dogs and still make at least $115?
57. Freight Handling The elevator of a building can safely carry no more than 4000 lb. A worker moves supplies in 50-lb boxes from the loading dock to the fourth floor of the building. The worker weighs 210 lb. The cart he uses weighs 95 lb.
    1. What is the greatest number of boxes he can move in one trip?
    2. The worker needs to deliver 275 boxes. How many trips must he make?

Standardized Test Prep

GRIDDED RESPONSE

SAT/ACT

58. The Science Club hopes to collect at least 200 kg of aluminum cans for recycling during a 21-week semester. The graph shows the first week's results. Let x represent the minimum average mass of cans required per week for the remainder of the semester. What is x?

    

59. What is the solution of 2 x + 8 = 4 x + 2 ? 2 x plus 8 equals 4 x plus 2 question mark
60. What is the solution of − 5 n − 16 = − 7 n ? negative 5 n minus 16 equals negative 7 n question mark
61. Great Gifts pays its supplier $65 for each box of 12 bells. The owner wants to determine the minimum amount x he can charge his customers per bell in order to make at least a 50% profit per box. What is x? Round to the nearest hundredth if necessary.

Mixed Review

See Lesson 3-3.

Solve each inequality.

62. − 9 m ≥ 36 negative 9 m greater than or equal to 36
63. − 24 ≤ 3 y negative 24 less than or equal to 3 y
64. y 5 > − 4 y over 5 , greater than negative 4
65. − t 3 ≤ 1 negative , t over 3 , less than or equal to 1

Get Ready! To prepare for Lesson 3-5, do Exercises 66–68.

See Lesson 1-3.

Determine whether each set represents the set of natural numbers, whole numbers, or integers .

66. the nonnegative integers
67. the counting numbers
68. …, − 3 , negative 3 comma   − 2 , negative 2 comma   − 1 , negative 1 comma  0, 1, 2, 3, …

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