f(x + h) - f(x) For the function f(x) = x~+7, find (a) f(x + h), (b) f(x + h) - f(x), and (c) h (a) f(x + h) =] (Simplify your answer.) (b) f(x + h) - f(x) = (Simplify your answer.) f(x + h) - f(x) (c) = h (Simplify your answer.)