y=mx+b
m=slope
b=y intercept
find slope
slope between the points (x1,y1) and (x2,y2) is (y1-y2)/(x1-x2)
so slope between (2,-2) and (3,2) is (-2-2)/(2-3)=-4/-1=4
y=4x+b
find b
using a point
(3,2)
x=3 and y=2
y=4x+b
2=4(3)+b
2=12+b
-10=b
y=4x-10 is the equation
