In this equation, F of X is five X + 30 / X ^2 + 6 X. The first thing we're going to do is factor the numerator and the denominator. So we're going to pull A5 out of the numerator and an X out of the denominator. Now, before we do any reducing, we need to figure out what the denominator can never ever equal, and the denominator can never be zero. So if I have a variable, I'm going to say that variable or that variable term if it's in parentheses, can't equal 0, so X cannot equal 0 and X + 6 cannot equal 0. Solving for X, we can see X can't equal 0 and X can't equal -6. So then we're going to reduce top and bottom that X + 6 / X + 6 is going to give us 5 / X where X is not zero and X is not -6.