x(x+1) - 4(2x-1) = 1(4)(x+1)

x^2 + x - 8x - 4 = 4x + 4

x^2 + x - 8x - 4 - 4x - 4 = 0

x^2 - 11x - 8 = 0

From there I factorise it to get the answer, but the answer it's supposed to be is 0 , 11

I can't see how that would work out unless it's just x^2 - 11x I think there may be a problem with the fours maybe but I'm not sure.