The perpendicular bisector goes through the midpoint.
What is the midpoint of the 2 points?
We simply add up the x points and divide by 2. Then we add up the y points and divide by 2.
So,
Midpoint is:

Also, the perpendicular bisector's slope is the negative reciprocal of the line's slope.
The slope of the line is change in y points divided by change in x points.
Slope =

The slope (m) of the perpendicular line (negative reciprocal) is basically:

Equation of line is:

m is the slope (what we got "2")
x1 and y1 are the respective point where it passes through (which is the midpoint, which is (-3,2)
So, equation of perpendicular bisector is:
