(3-x)

________

(3x^2-9x)

Now, we see that both 3x^2 and 9x are divisible by 3 (3x3, 3x1) and they also share x (x^2 = x*x). So we can change that into:

(3-x)

________

3x(x-3)

Here, we notice that (3-x) = -(x-3), so

-(x-3)

______

3x(x-3)

Divide both sides of the fraction by (x-3):

-1

___

3x

Now, input x=1 here to get -1/3

Note that if you want to graph this, the original domain still applies.