a/
\(\Leftrightarrow\left\{{}\begin{matrix}x-2\ge0\\3x^2-9x+1=\left(x-2\right)^2\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\ge2\\2x^2-5x-3=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x\ge2\\\left[{}\begin{matrix}x=3\\x=-\frac{1}{2}\end{matrix}\right.\end{matrix}\right.\) \(\Leftrightarrow x=3\)
b/ ĐKXĐ: \(x\le2\)
\(\Leftrightarrow x^2-2x+4=2-x\)
\(\Leftrightarrow x^2-x+2=0\) (vô nghiệm)
Vậy pt vô nghiệm