Answer:
y +8 = -4(x -8)
Explanation:
You recognize that the given equation is in slope-intercept form:
y = mx + b
with m = 1/4 and b = 5.
A perpendicular line will have a slope that is the negative reciprocal of this value of m, so the desired slope is ...
-1/m = -1/(1/4) = -4
The point-slope form of the equation for a line is ...
y -k = m(x -h) . . . . . for slope m through point (h, k)
Using m=-4 and (h, k) = (8, -8), the point-slope form of the equation for the line you want is ...
y +8 = -4(x -8)