Respuesta :

gronto
I think the answer is y=-3/1x+8

Explanation:

You turn it into y-intercept form because standard form is really hard to understand

x-3y=9
-3y=-x+9
3y=x-9
y=1/3-9

So now we see the slope is 1/3

And we know a perpendicular slope to that would be -3/1

Now if you just add 8 it crosses over point (3,-1)

Brainliest if this helps you?