8x-49^2-16 because -7x(4+7x) is broken down to -7x*4 = -28x and -7x*7x= -49x^2 the square root is because x*x= x^2 then you do the second part which is -8(2-4x) and again you break it down -8*2=-16 -8*-4x=36x so now you have -28x-49x^2-16+36x and when you simplify you get 8x-49^2-16