Question

The points (-5, 5) and (5, r) lle on a line with slope -3. Find the missing coordinate r.

Answer 1

r = -25

Explanation:

slope is change in "y" over change in "x"

so whatever your change in "x" is between the two points, the change in "y" needs to be in proportion to the slope of -3.

Here the change in "x" is +10, and to make the proportion of the slope equal to -3, the change in "y" needs to be -30.

Starting from the "y" coordinate of 5, a change in "y" of -30 will give you r = -25

So the two points are (-5, 5) and (5, -25)