- Earth Science The air tem p eratu re b e n e a th Earth's surface increases

by ab o u t 10°C p er kilometer. The surface tem p eratu re a n d th e air

tem p eratu re at th e b o tto m of a m ine are show n. How m an y kilom eters

below Earth's surface is the b o tto m of th e m ine? - Car-Sharing Program M em bers of a car-sharing program pay a fee of

$50 p e r m o n th plus $7.65 for every h o u r they use a car. A m em b er's bill

was $149.45 last m onth. How m any h ours did th e cu sto m er use a car

last m onth?

`Challenge 61. Word Processing You form at a d o c u m en t in th ree colum ns of equal`

w idth. The d o cu m en t is 8.5 in. wide. You w a n t left an d right m argins

of 1 in. each. B etw een th e colum ns th ere is a "gutter" th a t is one eighth as wide as

each colum n. W hat is the w idth of each colum n?

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

why not.

2

`Bottom o f mine: 38°C`

N o t d ra w n t o scale

c

`\< S?`

- 2 x - 0 = 0 63. 0(—2x) = 4 64. 0 65.

St a n d a r d i ze d Test Pr ep GRIDDED RESPONSE

SAT/ACT 66. William ’s age w an d Jam ie’s age j are related by th e eq u a tio n w = 2/ — 12. W hen

William is 36.5 years old, how old is Jamie?

- D om inique p ain ts faces at an an n u a l carnival. H er goal this year is to ea rn $100.

She spends $15 on supplies an d will w ork for 2.5 h. How m u ch will she n e e d to earn

in dollars p er h o u r in o rder to reach h er goal?

`68. The cost of a gallon of milk m is $.50 m ore th a n five tim es th e cost of a gallon of`

water w. If a gallon of m ilk costs $3.75, w h at is th e cost of a gallon of water?

Mixed Review

`Solve each equation.`

- -5 x = -25 70. 7 = 3.2 +y 71. £ = 36

`See Lesson 2-1.`

- z- 2 = 4.5

Tell whether each statement is true or false. If it is false, give a counterexample. ^ See Lesson 1-4.

- The difference of the absolute value of two n u m b e rs is th e sam e as th e difference of

the two n u m b ers them selves. - Adding 1 to a n u m b e r always increases its absolute value.

`Get Read y! To p r e p a r e fo r Lesson 2 - 3 , d o E xercises 7 5 - 7 8.`

Simplify each expression.

75.7(5 -t) 76. -2 (-2 x + 5 ) 77. -3(2 - b)

`See Lesson 1-7.`

- 5(2 - 5n)

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`PowerAlgebra.com | Le sso n 2 - 2 So l v i n g Tw o - St e p Eq u a t i o n s^93`