To simplify this problem you need to do FOIL which stands for first, outer, inner, and last. That is the order that you do the multiplication in. So fist you multiply 4x and 5x you end up with 20x^2. The exponent shows up because it is x times x and that simplified is x^2. Then you do the outer numbers. 4x times -1 = -4x. Next you do the inner numbers 1 times 5x= 5x. Then you do the last numbers 1 times -1 = -1. After you do all of these steps you put the equation back together and it is 20x^2 +5x-4x-1 then you combine like terms and end up with 20x^2+x-1
Hope this helped you!!!
