#### Answer

$ f(4)=-2$,
$ f'(4)=3$

#### Work Step by Step

The equation of the tangent line is
$ y=f(a)+f'(a)(x-a)$
This implies that
$ f(4)+f'(4)(x-4)=3x-14$
From the above equation, we have
$ f'(4)\times x=3x $ and $[f(4)-4\times f'(4)]=-14$
Thus, we obtain
$ f'(4)=3$ and $ f(4)=-14+(4\times3)=-2$