ĐKXĐ: \(\left[{}\begin{matrix}x\le-2\\x\ge2\end{matrix}\right.\)
Ta có:
\(\sqrt{x^2-4}=x-2\)
\(\Leftrightarrow\left\{{}\begin{matrix}x-2\ge0\\x^2-4=x^2-4x+4\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\ge2\\4x-8=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\ge2\\x=2\end{matrix}\right.\)
\(\Leftrightarrow x=2\)(thỏa mãn ĐKXĐ)
Vậy x = 2