Question 580484
(x+4)^2 =(x+4)(x+4) = x*x + 4x + 4x + 4*4 = x^2 + 4x + 4x + 16 = x^2 + 8x + 16



So (x+4)^2 = x^2 + 8x + 16 for all values of x.