Graphing functions

f (x) = x^2-6x-27/x+3

Funny, this looks like a complex graph, until you realize that the numerator can be written like (x+3) (x-9).

So really, this is a straight line f (x) = x-9.

But wait, there's a catch. x≠3, because that would divide by zero. So in your straight line, you have to draw a "hole" at (3,6)