Giải các hệ :
$\begin{array}{l}
1)\,\,\,\left\{ \begin{array}{l}
{\log _x}\left( {x + 2} \right) >
2\,\,\,\,\,\,\,\,\,\,\,\,\,(1)\\
{\log _2}{2^{x - 1}} + {\log _2}\left( {{2^{x + 1}} + 1} \right) < {\log _2}\left( {{{7.2}^x} + 12}
\right)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,(2)
\end{array} \right.\\
2)\,\,\,\left\{ \begin{array}{l}
{\log _{7 - x}}\left( {y - 4} \right) < 0\\
{\log _{y - 1}}\left( {3 - x} \right) < 0
\end{array} \right.
\end{array}$
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