Question 642640
f(x) = x^2 + 2x + 1


f(x+h) = (x+h)^2 + 2(x+h) + 1


f(x+h) = (x^2+2xh+h^2) + 2(x+h) + 1


f(x+h) = x^2+2xh+h^2 + 2x+2h + 1