m is simply the slope of the line. The equation for m or slope is given as:
m = (y2 – y1) / (x2 – x1)
Therefore we can find for r by substituting the values:
- 4 = (-6 – (-2)) / (r – 8)
- 4 = - 4 / (r – 8)
r – 8 = 1
r = 9
So:
(r, -6) = (9, -6)
