Question

On a cartesian coordinate plane, point a is at (-2, 2) and point b is at (1, -4) what is the equation for line ab

Answer 1

The slope of this line is

         2-(-4)
m = ------------ = -6/3 = -2.
        -2 - 1

Starting with y = mx + b, -4 = -2(1) + b, or     -4 = -2 + b.  Then b= -2, and the
equation is

y = -2x -2.