Example 2 Positive and Negative Slope

Find the slope of the line.

a.=runrise

m =x1x2

y1y2

–

–

15

27

–

–=

4

5=

Example 2 Positive and Negative Slope

Find the slope of the line.

24

63

–

–=

2

– 3= or

2

3–

b. =

x1x2

y1y2

–

–=runrise

m

Example 3 Zero and Undefined Slope

Find the slope of the line.

26

33

–

–=

4

0=

=

0a.

=x1x2

y1y2

–

–=runrise

m

Example 3 Zero and Undefined Slope

Find the slope of the line.

0

6=

11

4

––

=( )2–

The slope is undefined.

b. =

x1x2

y1y2

–

–=runrise

m

for Examples 2 and 3Guided Practice

Find the slope of the line passing through the points.

ANSWER 0

4. (–3, –4), (5, 2)

5. (1, 5), (–3, 5)

2. (2, 1), (6, 4)

3. (0, 6), (10, 0)

ANSWER4

3

ANSWER5

3–

ANSWER4

3

for Examples 2 and 3Guided Practice

Find the slope of the line passing through the points.

ANSWER undefined

ANSWER 0

6. (1, 6), (1, 2)

7. (–8, 3), (8, 3)