Suppose you have to factor a polynomial like x2 − 5x + 6. That is, there's nothing in front of the x2, but there can be a linear term and a constant term. You need to find two numbers whose sum is 6 (the constant term) and whose product is −5 (the number in front of the x). The numbers that work are −2 and −3. (It doesn't matter what order we put them in.) Then the two factors are x − 2 and x − 3, so the answer is (x − 2)(x − 3).