Find f' (x) for the following function. Then find f (5), f (0), f (-9).

f (x) = 2x+1 (simplify)

If f' (x) means the derivative, or gradient, of f, then the answer is 2.

f (5) = 11, f (0) = 1 and f (-9) = - 17.

We can calculate the gradient using these values:

Gradient = (11-1) / (5-0) = (-17-1) / (-9-0) = (-17-11) / (-9-5) = 2.