1. If $g(x)=\frac{x-2}{x}$ and $f(-g(-x))=\frac{x-2}{2 x-6}$, find $f(3)$.
Answer: $\frac{5}{14}$
Solution: Note that $-\frac{-x-2}{-x}=3 \Longrightarrow x=-\frac{1}{2}$. Hence $f(3)=\frac{-\frac{1}{2}-2}{2\left(-\frac{1}{2}\right)-6}=\frac{5}{14}$.