College Algebra
Answer/Discussion to Practice
Problems
on Slope of a Line
 Answer/Discussion
to 1a
(2, -5) and (-1, -1) |
 |
*Plug in x and
y
values into slope formula
*Simplify
|
| Make sure that you are careful when one of
your values is negative and you have to subtract it as we did in line 2.
-5 - (-1) is not the same as -5 - 1 and 2 - (-1) is not the same as 2 -
1.
The slope of the line is -4/3.
Since the slope is negative, the line would fall (left to right). |
| Answer/Discussion
to 1b
(7, 1) and (7, 2) |
 |
*Plug in x and
y
values into slope formula
*Simplify
|
| The slope of the line is undefined.
Since the slope is undefined, the line is vertical. |
| Answer/Discussion
to 1c
(1, 7) and (-2, -2) |
 |
*Plug in x and
y
values into slope formula
*Simplify
|
| Make sure that you are careful when one of
your values is negative and you have to subtract it as we did in line 2.
7 - (-2) is not the same as 7 - 2 and 1 - (-2) is not the same as 1 - 2.
The slope of the line is 3.
Since the slope is positive, the line would rise (left to right). |
| Answer/Discussion
to 1d
(-1, -5) and (-4, -5) |
 |
*Plug in x and
y
values into slope formula
*Simplify
|
| Make sure that you are careful when one of
your values is negative and you have to subtract it as we did in line 2.
-5 - (-5) is not the same as -5 - 5 and -1 - (-4) is not the same as -1
- 4.
The slope of the line is 0.
Since the slope is zero, the line is horizontal. |
All contents copyright (C) 2002 - 2008, WTAMU and Kim Seward. All rights reserved.
Last revised on August 25, 2002 by Kim Seward. |
