Answer
y=7x-44
Work Step by Step
You have to rewrite the equation x+7y-12=0 in slope intercept form.
7y-12=-x
so i subtracted the x on both sides.
Then add the 12 to both sides.
7y=-x+12
divide the 7.
y=$\frac{-x}{7}$+$\frac{12}{7}$
Since it's perpendicular it has to have a slope thats reciprocal.
y=7x+b
substitute the values and solve for b.
-9=$7\times5$+b
-44=b
So the answer is y=7x-44