23.Concept Check On the basis of the figure shown here,
determine which line satisfies the given description.
(a)The line has positive slope.
(b)The line has negative slope.
(c)The line has slope 0.
(d)The line has undefined slope.
24.Which of the following forms of the slope formula are correct? Explain.
A. B. C. D.For Exercises 25 –36, (a)find the slope of the line through each pair of points, if possible, and
(b)based on the slope, indicate whether the line through the points risesfrom left to right,
fallsfrom left to right, is horizontal,or is vertical.See Examples 1 and 3 andFIGURE 20.
- and 26. and 27. and
- and 29. and 30. and
- and 32. and 33. and
- 1 4, - 12 and 1 4, 3 2 35. 1 1.5, 2.6 2 and 1 0.5, 3.6 2 36.
1 - 2, 2 2 1 4, - 12 1 - 3, 1 2 1 6, - 22 1 5, - 32 1 5, 2 2
1 - 3, - 32 1 5, 6 2 1 2, 4 2 1 - 4, 4 2 1 - 6, 3 2 1 2, 3 2
1 - 2, - 32 1 - 1, 5 2 1 - 4, 1 2 1 - 3, 4 2 1 - 4, 1 2 1 2, 6 2
m=y 2 - y 1
x 2 - x 1m=x 2 - x 1
y 2 - y 1m=y 1 - y 2
x 1 - x 2m=y 1 - y 2
x 2 - x 1SECTION 3.2 The Slope of a Line 157
yxABCD01 3.4, 4.2 2 and 1 1.4, 10.2 2Brain Busters Find the slope of the line through each pair of points. Hint:
- and 38. and
- and 40. and
Find the slope of each line.
a-3
10
,
1
5
a- b4
5
,
9
10
a b1
18
, -
5
9
a- b2
9
,
5
18
ba5
4
,
10
3
a b3
4
,
1
3
a b5
6
,
9
2
a b1
6
,
1
2
b=
a
b,
c
dba
b
c
da22
xy–22
xy–22
xyCalculate the value of each slope m,if possible, by using the slope formula. See Example 1.
18. 19. 20.
- 22.m=
5 - 6
- 8 - 1 - 82
m=3 - 8
- 2 - 1 - 22
m=- 2 - 1 - 22
4 - 1 - 32
m=- 5 - 1 - 52
3 - 2
m=- 6 - 0
0 - 1 - 32
m=4 - 1 - 12
- 3 - 1 - 52
m=5 - 7
- 4 - 2
m=