Well, even though you're in Calculus, it's okay that you've momentarily forgotten how to factor. Brain farts happen to the best of us. My first step here would be to find a common factor and pull it out. You have three terms there. Do they have any common factors? For instance, do they all contain an x? Are they all divisible by some number? Once you do that, you should have two terms multiplied together, one of which is a standard quadratic of the form:
x^2 + bx + c = (x+?)(x+?)
Now remember back to the rules for factoring you learned so long ago back in Algebra class. You want to find two numbers which multiply to c and add up to b. Can you do that? It might help if you list all the factors of c.