\(\left(x+2\right)\left(x+7\right)\le0\)
\(\Rightarrow\hept{\begin{cases}x+2\ge0\\x+7\le0\end{cases}}\) hoặc \(\hept{\begin{cases}x+2\le0\\x+7\ge0\end{cases}}\)
\(\Rightarrow\hept{\begin{cases}x\ge-2\\x\le-7\end{cases}}\) hoặc \(\hept{\begin{cases}x\le-2\\x\ge-7\end{cases}}\)
\(\Rightarrow-7\le x\le-2\)
\(\Rightarrow x\in\left\{-7;-6;-5;-4;-3;-2\right\}\)