CPM Homework Help : PC Problem 8-144

Given $f (x) = x^2 + x + 1$ , find $f \left(x + h\right) − f \left(x\right)$ .

Step:

$f(x + h) − f(x) = ((x + h)^2 + (x + h) + 1) − (x^2 + x + 1)$
Simplify.