Question

Find the slope of the line that contains the points (1,-1) and (-2,8)

Answer 1

The formula for slope is (y-y1)/(x-x1).
1 = x
-1 = y
-2 = x2
8 = y2

You would plug those into the formula: (-1-(-2))/(-1-8) and that would equal to: 1/(-9).