Đáp án:$\begin{array}{l}
\frac{{x - 1}}{{x + 5}} = \frac{6}{7}\left( {dkxd:x \ne - 5} \right)\\
\Rightarrow 7\left( {x - 1} \right) = 6\left( {x + 5} \right)\\
\Rightarrow 7x - 7 = 6x + 30\\
\Rightarrow x = 37\,\left( {tmdk} \right)
\end{array}$
Vậy x=37