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.