Lời giải:
PT $\Leftrightarrow x-3=3\sqrt{x-1}$
\(\Rightarrow \left\{\begin{matrix} x-3\geq 0\\ (x-3)^2=9(x-1)\end{matrix}\right.\Leftrightarrow \left\{\begin{matrix} x\geq 3\\ x^2-15x+18=0\end{matrix}\right. \)
$\Rightarrow x=\frac{3}{2}(5+\sqrt{17})$