\(\left(x+2\right)\sqrt{x^2-2x+4}=x^2+4x+4\)
( TXĐ : R )
\(\Leftrightarrow\left(x+2\right)\sqrt{x^2-2x+4}=\left(x+2\right)^2\)
\(\Leftrightarrow\left[{}\begin{matrix}x+2=0\\\sqrt{x^2-2x+4}=x+2\end{matrix}\right.\)
\(\Leftrightarrow\)\(\left[{}\begin{matrix}x=-2\\\left\{{}\begin{matrix}x\ge-2\\x^2-2x+4=\left(x+2\right)^2\end{matrix}\right.\end{matrix}\right.\)
\(\Rightarrow\)\(\left[{}\begin{matrix}x=-2\\\left\{{}\begin{matrix}x\ge-2\\x=0\end{matrix}\right.\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=0\end{matrix}\right.\)
