Try another version of this question Given `f(x) = x^2 + 3 x `, find the average rate of change of `f(x)` on the interval `[4, 4+h]`. Your answer will be an expression involving `h`.
Box 1: Enter your answer as an expression. Example: 3x^2+1, x/5, (a+b)/c
Be sure your variables match those in the question `11 + h`