Question

What is the slope of a line perpendicular to the line whose equation is 3x-9y=216. Fully reduce your answer.

Answer 1

-9y=-3x+216
y=1/3x-24
m=-3
y=-3x+16 is perpendicular to the line

Answer 2

First, convert it to slope intercept form. That would make it: 

$y= \frac{1}{3} x-24$

Then, change the slope by finding its negative reciprocal, since it is perpendicular

$y= -3x-24$