Question

(-9,-6) perpendicular to x=3

Answer 1

x=3 is a vertical line, which has no slope
a perpendicular line will have a slope of 0 because it will be a horizontal line
y=mx+b fill in what you know
-6=-9(0)+b
-6=b y=ox-6 or y=-6

Answer 2

i have another question
F(x)=5x^2-3x+6 Find f(k-1)