You are looking for 2 numbers that multiply to give 6 and that either add or subtract to give 5. Well, the following numbers multiply to give 6. 1 * 6. 2 * 3. These are the only whole numbers that can multiply to make 6 (x + 2)(x - 3) = x^2 - x - 6 so this dosen't work. Lets try (x + 1)(x - 6) = x^2 - 5x - 6
