The first two terms have 2*x* in common, which we can factor out to find 2*x*(*x* + 7) - 3*x* - 21. For the second two terms, we could factor out 3 or we could factor out - 3. Whoa! Rein in your pony there, cowboy. If we factor out 3, we'll find 2*x*(*x* + 7) + 3(-x - 7). Those two terms don't have a common factor. Instead, if we had factored out - 3 we would get 2*x*(*x* + 7) - 3(*x* + 7) and we could pull out (*x* + 7) to see that (2*x* - 3)(*x* + 7). |