Answer
$$1$$
Work Step by Step
\begin{align*}
\lim _{x \rightarrow 1^{-}}\left(\frac{1}{x+1}\right)\left(\frac{x+6}{x}\right)\left(\frac{3-x}{7}\right)
&=\left(\frac{1}{1+1}\right)\left(\frac{1+6}{1}\right)\left(\frac{3-1}{7}\right)\\
&=\left(\frac{1}{2}\right)\left(\frac{7}{1}\right)\left(\frac{2}{7}\right)\\
&=1
\end{align*}