Subtract the 2 over from the 3 which leaves you with 1 as the constant. Then you have 7b^2-8b+1. Slide the 7 over to the 1 using the slide and divide method. This leaves you with b^2-8b+7. Then just think "what multiplies to get 7, and adds to -8." The answer to that is (x-7)(x-1). Then you have to divide by 7 because you slid it earlier. So that gives you the answer of : (x-1)(7x-1).