When we come across questions like this, we expand by multiplying everything in the first bracket by everything in the second bracket. An easier way of doing this is rewriting the question like: x(3x+4) + 3(3x+4) and then we would expand these brackets out. The first bracket expands to 3x2+4x, and the second bracket expands to 9x+12. When we add up all the components we get 3x2+4x+9x+12. We must simplify this so we get, 3x2 +13x+12 which is our answer.