Answer
$$ f'(3)=5, \quad f(3)=17.$$
Work Step by Step
Since the tangent line at $ x=3, $ has the equation
$$ y=5x+2,$$
then $ f'(3)$ is the slope, that is, $$ f'(3)=5.$$
Moreover, the tangent line at $ x=3$ coincides with the function itself, that is, $$ f(3)=5(3)+2=15+2=17.$$
