Question 201495
f(x) = 8x + 4
f(x + h) = 8(x + h) + 4 = 8x + 8h + 4
f(x + h) - f(x) = (8x + 8h + 4) - (8x + 4) = 8h
{{{(f(x + h) - f(x))/h = (8h)/h = 8}}}