Answer: y = -x - 16
========================================================
Explanation:
The given equation is the same as y = 1x+5 which is in y = mx+b form.
- m = slope = 1
- b = y intercept = 5
Anything perpendicular to this will have a slope of -1, which is the negative reciprocal of the original slope.
We'll use this perpendicular slope along with (x,y) = (-20,4) to find the equation of the perpendicular line.
y = mx+b
y = -1x+b ... plug in the perpendicular slope
4 = -1*(-20)+b ... plug in the x,y coordinates
4 = 20+b
4-20 = b
-16 = b
b = -16
Therefore, we go from y = mx+b to y = -x-16
