# Calculate the Slope of a Line – Practice Questions

- Posted by Brian Stocker
- Date February 25, 2019
- Comments 1 comment

### Finding the Slope of a Line

The **slope** of a line is the *direction* and the *steepness* of the line.^{} Slope is usually the letter *m*; ^{}

Slope is calculated by finding the ratio of the “vertical change” to the “horizontal change” between two points on a line. Sometimes the ratio is expressed as a quotient (“rise over run”), giving the same number for every two points on the line. A line that is decreasing has a negative “rise” and a negative slope.

- If a line is horizontal the slope is
**zero**. - A line is
**decreasing**if it goes**down**from left to right. The slope is**negative**, i.e. . - A line is
**increasing**if it goes**up**from left to right. The slope is**positive**, i.e. . - If a line is vertical the slope is
*undefined*

The rise of a line, between two points, is the difference between the height at those two points, *y*_{1} and *y*_{2}, so the equation is (*y*_{2} − *y*_{1}) = Δ*y*. In basic geometry, we examine short distances, otherwise we would have to incorporate the curvature of the earth. The run, is the difference in distance from a fixed point along a horizontal line, or (*x*_{2} − *x*_{1}) = Δ*x*.

The equation to calculate the slope of a line, *m,* is:

### Calculate the Slopr of a Line - Practice Questions

1. What is the correct order of respective slopes for the lines above?

a. Positive, undefined, negative, positive

b. Negative, zero, undefined, positive

c. Undefined, zero, positive, negative

d. Zero, positive undefined, negative

2. Find the slope of the line above.

a. 5/4

b. -4/5

c. -5/4

d. -4/5

3. What is the slope of the line above?

a. 1

b. 2

c. 3

d. -2

4. What is the slope of the line above?

a. -8/9

b. 9/8

c. -9/8

d. 8/9

5. With the data given above, what is the value of y1?

a. 0

b. -7

c. 7

d. 8

### Answer Key

**4. A**

(x1, y1) = (-9, 6) & (x2, y2) = (18, -18)

Slope=(-18 – 6) / [18 – (-9)] = -24/27= -(8/9)

**Written by**, Brian Stocker MA., Complete Test Preparation Inc.

## 1 Comment

This question is not clear to me.