Question 1016654
First, find the slope.
m = (y2-y1) / (x2-x1) = (-5-4)/(-8-(-7)) = -9/-1 = 9
Now plug one point and the slope into
y = mx + b to find b...
4 = 9(-7) + b
b = 67
so you have
y = 9x + 67
Now rearrange and get
-9x + y = 67