Question

A line that includes the points (8,-8) and (r,0) has a slope of -8/9. What is the value of r?

Answer 1

r = -1

Explanation:

Slope between two points is determined by (y2-y1)/(x2-x1)

In this case, we would get (-8-0)/(8-r), making:
-8/(8-r) = -8/9

8-r = 9 because you want the denominator to equal 9, and therefore when you input r as -1, we get the denominator to have the value of 9.