\(\sqrt{x-6-4\sqrt{x-2}}=5\)
\(\sqrt{x-6-\sqrt{\left(2x-2\right)^2}}=5\)
\(\sqrt{x-6-2x-2}=5\)
\(\sqrt{-x-8}=5\)
\(\left\{{}\begin{matrix}5\ge0\left(luon\cdot dung\right)\\-x-8=25\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}5\ge0\left(luon\cdot dung\right)\\x=-33\left(l\right)\end{matrix}\right.\)