$\left\{ \begin{array}{l}\sqrt{x-1}-x+3y-2\sqrt[3]{3y+2}=1\\ x+\sqrt{x-1}-3y-2\sqrt[3]{3y+2} =-7\end{array} \right$.
\Leftrightarrow \left\{ \begin{array}{l} 2x-6y=-8\\ 2\sqrt{x-1}-4\sqrt[3]{3y+2}=-6\end{array} \right.
\Leftrightarrow \left\{ \begin{array}{l} x=3y-4 (1)\\ \sqrt{x-1} =\sqrt[3]{3y+2}-3 (2)\end{array} \right.
thay (1) vao` (2) ta co': \sqrt{3y-5}=\sqrt[3]{3y+2}-3
Dat. t=\sqrt[3]{3y+2} giai tim` t\rightarrowy\rightarrowx