Question 82969
Its difficult to explain a process for working this out, it's a matter of practice really.

You should be able to check my expression below with the worded question and that might help you if you get another pro like this.

{{{(9/(x-3))-(x^2/(x-3))}}}
because both parts have the same denominator, we can simplify the expression to
{{{(9-x^2)/(x-3)}}}


I hope this helps
Adam