C Challenge

62. You can find the equation of a line through two points even if one point is not the y-intercept.
    • Find the slope m of the line passing through the two points.
    • Using either point, substitute for x, y, and m into y = m x + b . y equals m x plus b .
    • Solve for b and rewrite y = m x + b y equals m x plus b  for the values of m and b.

    Write an equation in slope-intercept form for the line passing through each pair of points.

    1. (2, 5) and (6, 7)
    2. ( − 4 , 16 ) open negative 4 comma 16 close  and ( 3 , − 5 ) open 3 comma negative 5 close
    3. ( − 2 , 17 ) open negative 2 comma 17 close  and (2, 1)

Standardized Test Prep

SAT/ACT

63. Which equation does NOT represent a direct variation?
    1. y − 3 x = 0 y minus , 3 x equals 0
    2. y + 2 = 1 2 x y plus 2 equals , 1 half , x
    3. y x = 2 3 y over x , equals , 2 thirds
    4. y = x 17 y equals , x over 17

64. Which equation models the data in the table?

    x	y
    1	4
    2	7
    3	12
    4	19

    6. y = x 2 − 1 y equals , x squared , minus 1
    7. y = x 2 + 3 y equals , x squared , plus 3
    8. y = − x 2 + 3 y equals negative , x squared , plus 3
    9. y = x 2 + 1 y equals , x squared , plus 1
65. In the formula V = 1 3 π r 2 h , v equals , 1 third , pi , r squared , h comma  which expression is equal to h?
    1. V 3 π r 2 fraction v , over 3 pi , r squared end fraction
    2. V − 1 3 π r 2 v minus , 1 third , pi , r squared
    3. 3 V π r 2 fraction 3 v , over pi , r squared end fraction
    4. 3 V π r 2 fraction 3 v pi , over r squared end fraction

Short Response

66. Graph the relation { ( − 2 , 1 ) , ( 0 , 2 ) , ( − 1 , − 1 ) , ( − 2 , − 2 ) } . left brace open negative 2 comma 1 close comma open 0 comma 2 close comma open negative 1 comma negative 1 close comma open negative 2 comma negative 2 close right brace .  What are the domain and range?

Mixed Review

See Lesson 2-1.

Find the domain and range of each relation, and determine whether it is a function.

67. 
68. 
69. 
    Image Long Description

Get Ready! To prepare for Lesson 2-4, do Exercises 70–72.

See Lesson 1-3.

Evaluate each expression for x = 0.

70. 5 x + 2 5 x plus 2
71. ( x − 4 ) + 12 open x minus 4 close plus 12
72. 13 − 6.5 x 13 minus 6.5 x

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