\[\boxed{\mathbf{793}\mathbf{.}}\]
\[a > 0;a \neq 1;x_{1} \neq 0;\ \ x_{2} \neq 0.\]
\[1)\log_{a}\left| x_{1} \cdot x_{2} \right| =\]
\[= \log_{a}\left( \left| x_{1} \right| \cdot \left| x_{2} \right| \right) =\]
\[= \log_{a}\left| x_{1} \right| + \log_{a}\left| x_{2} \right|\]
\[2)\ \log_{a}\left| \frac{x_{1}}{x_{2}} \right| = \log_{a}\frac{\left| x_{1} \right|}{\left| x_{2} \right|} =\]
\[= \log_{a}\left| x_{1} \right| - \log_{a}\left| x_{2} \right|\]