# How do you find the function values f(0) given F(x) = -4x?

To find the function value for $f \left(0\right)$ you substitute $0$ for each occurrence of $x$ in the function.
$f \left(\textcolor{red}{x}\right) = - 4 \textcolor{red}{x}$ for $0$ becomes $f \left(\textcolor{red}{0}\right) = - 4 \times \textcolor{red}{0}$
$f \left(\textcolor{red}{0}\right) = 0$