\(\Leftrightarrow\left|x+2\right|^2-3\left|x+2\right|=0\)
\(\Leftrightarrow\left|x+2\right|\left(\left|x+2\right|-3\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left|x+2\right|=0\\\left|x+2\right|=3\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x+2=0\\x+2=3\\x+2=-3\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=1\\x=-5\end{matrix}\right.\)
