The slope of CD is
The slope of the perpendicular bisector is the negative reciprocal,
The perpendicular bisector passes through M, the midpoint of CD
M =( (0+2)/2, (-4 + 6)/2) = (1, -1)
So point slope form for the perpendicular bisector is
Solving for y gives slope intercept form.
Not sure how to type that without spaces; we didn't have online homework back then.
Answer: y=(-1/5)x-4/5