Перемножьте почленно неравенства: 1/7<1/6 и 6/7<1.

\[\frac{1}{7} < \frac{1}{6}\ \ \ и\ \ \frac{6}{7} < 1\]

\[х\left| \begin{matrix}
\frac{1}{7} < \frac{1}{6} \\
\frac{6}{7} < 1 \\
\end{matrix} \right.\ \]

\[\overline{\text{\ \ \ \ }\frac{6}{49} < \frac{1}{6}\text{\ \ }}\]