59. Earth Science The air temperature beneath Earth's surface increases by about 10°C per kilometer. The surface temperature and the air temperature at the bottom of a mine are shown. How many kilometers below Earth's surface is the bottom of the mine?

    

60. Car-Sharing Program Members of a car-sharing program pay a fee of $50 per month plus $7.65 for every hour they use a car. A member's bill was $149.45 last month. How many hours did the customer use a car last month?

    C Challenge

61. Word Processing You format a document in three columns of equal width. The document is 8.5 in. wide. You want left and right margins of 1 in. each. Between the columns there is a “gutter” that is one eighth as wide as each column. What is the width of each column?

Tell whether each equation has a solution. If so, find the solution. If not, explain why not.

62. 2 x − 0 = 0 2 x minus 0 equals 0
63. 0 ( − 2 x ) = 4 0 open negative 2 x close equals 4
64. x − 2 2 = 0 fraction x minus 2 , over 2 end fraction . equals 0
65. x − 2 0 = 2 fraction x minus 2 , over 0 end fraction . equals 2

Standardized Test Prep

GRIDDED RESPONSE

SAT/ACT

66. William's age w and Jamie's age j are related by the equation w = 2 j − 12 . w equals 2 j minus 12 .  When William is 36.5 years old, how old is Jamie?
67. Dominique paints faces at an annual carnival. Her goal this year is to earn $100. She spends $15 on supplies and will work for 2.5 h. How much will she need to earn in dollars per hour in order to reach her goal?
68. The cost of a gallon of milk m is $.50 more than five times the cost of a gallon of water w. If a gallon of milk costs $3.75, what is the cost of a gallon of water?

Mixed Review

See Lesson 2-1.

Solve each equation.

69. − 5 x = − 25 negative 5 x equals negative 25
70. 7 = 3.2 + y
71. y 4 = 36 y over 4 , equals 36
72. z − 2 = 4.5 z minus 2 equals 4.5

See Lesson 1-4.

Tell whether each statement is true or false. If it is false, give a counterexample.

73. The difference of the absolute value of two numbers is the same as the difference of the two numbers themselves.
74. Adding 1 to a number always increases its absolute value.

Get Ready! To prepare for Lesson 2-3, do Exercises 75–78.

See Lesson 1-7.

Simplify each expression.

75. 7 ( 5 − t ) 7 open 5 minus t close
76. − 2 ( − 2 x + 5 ) negative 2 open negative 2 x plus 5 close
77. − 3 ( 2 − b ) negative 3 open 2 minus b close
78. 5 ( 2 − 5 n ) 5 open 2 minus 5 n close

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