The points -5, -24 and 5,r lie on a line with slope 4. Find the missing coordinate r. Slope = (y2 -

The points -5, -24 and 5,r lie on a line with slope 4. Find the missing coordinate r.

Slope = (y2 - y1)/(x2 - x1)

Plugging in our numbers, we get:
4 = (r - -24)/(5 - -5)
4 = (r +24)/10

Cross multiply:
r + 24 = 40

Subtract 24 from each side:
r = 16