How do you factorise x^2 + 3x + 2?

Since there is an x^2 term, we know that there are two brackets that are of the form (x-) (x-), but we need to fill in the blanks! What are the two numbers where you can add them up to make 3, and you can multiply them together to make 2? Here we can see 2 and 1 satisfy the criteria, so the answer is (x-2)(x-1).