Graph each line described. See Example 5.
57.Through ; 58.Through ;
59.y-intercept ; 60.y-intercept ;
61.Through ; 62.Through ;
- ; through 64. ; through
65.Undefined slope; through 66.Undefined slope; through
67.Concept Check If a line has slope , then any line parallel to it has slope , and
any line perpendicular to it has slope.
68.Concept Check If a line has slope 0.2, then any line parallel to it has slope , and
any line perpendicular to it has slope.
Decide whether each pair of lines is parallel, perpendicular,or neither.See Examples 6 –8.
1 - 3, 1 2 1 - 4, 1 2
m= 0 1 2, - 52 m= 0 1 5, 3 2
1 - 1, - 22 m= 3 1 - 2, - 42 m= 4
1 0, - 22 m=- 23 1 0, - 42 m=- 23
1 - 4, 2 2 m= 21 1 - 2, - 32 m= 45
158 CHAPTER 3 Graphs, Linear Equations, and Functions
69.The line through and
and the line through and
70.The line through and and
the line through 1 - 5, 5 2 and 1 7, 4 2
1 4, 6 2 1 - 8, 7 2
1 5, - 202
1 8, - 42
1 15, 9 2 1 12, - 72
- and 72. and
- and 74. and
- and 76. and
- and 78. and
- and 80. and
Concept Check Find and interpret the average rate of change illustrated in each graph.
2 x=y+ 3 2 y+x= 3 4 x- 3 y= 8 4 y+ 3 x= 12
4 x+y= 0 5 x- 8 = 2 y 2 x+ 5 y=- 8 6 + 2 x= 5 y
x= 6 6 - x= 8 3 x=y 2 y- 6 x= 5
4 x- 3 y= 6 3 x- 4 y= 2 2 x+y= 6 x-y= 4
x+ 4 y= 7 4 x-y= 3 2 x+ 5 y=- 7 5 x- 2 y= 1
02341
4
8
12
16
20
x
y
Year
Value of Machine
(in thousands of dollars) 01 234
100
200
300
400
x
y
Month
Amount Saved
(in dollars)
01 234
2
4
6
8
x
y
Year
Percent of Pay Raise
84.Concept Check If the graph of a linear equation rises from left to right, then the
average rate of change is. If the graph of a linear equation falls from
(positive/negative)
left to right, then the average rate of change is.
(positive/negative)
44.Concept Check Let kbe the number of letters in your last name. Sketch the graph of
What is the slope of this line?
Find the slope of the line and sketch the graph. See Examples 1– 4.
- 54.y=- 4 55. 2 y= 3 56. 3 x= 4
x- 3 = 0 x+ 2 = 0 y=- 5
4 x-y= 4 y= 4 x y=- 3 x
x+ 2 y= 4 x+ 3 y=- 6 5 x- 2 y= 10
y=k.
