This is a relative simple problem. We just need to isolate y
I'm going to assume you have no experience doing this and will walk you through step by step
-9x+3y+27=0
Add 9x to each side to keep equation the same. Whatever we do to one side, we must to the other side. We do this because the equation qould be different and thus the answer wrong if we didn't
3y+27=9x
Subtract 27
3y=9x-27
Now to get rid of the 3 on the y, we need to divide, because the 3 is multiplying the y. To "move" one thing from one side to the other, do the opposite of what it is doing
y=3x-9
It is now in intercept form.