ĐKXĐ: \(x\le1\).
\(PT\Leftrightarrow x^2-2x+1=1-x-12\sqrt{1-x}+36\)
\(\Leftrightarrow\left(x-1\right)^2=\left(\sqrt{1-x}-6\right)^2\)
\(\Leftrightarrow\left[{}\begin{matrix}x+5=\sqrt{1-x}\left(1\right)\\7-x=\sqrt{1-x}\left(2\right)\end{matrix}\right.\).
\(\left(1\right)\Leftrightarrow\left\{{}\begin{matrix}x\ge-5\\\left(x+5\right)^2=1-x\end{matrix}\right.\Leftrightarrow x=-3\).
\(\left(2\right)\Leftrightarrow\left(7-x\right)^2=1-x\Leftrightarrow x^2-13x+48=0\) (vô nghiệm).
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