ĐKXĐ: \(-\frac{1}{3}\le x\le2\)
\(\Leftrightarrow\sqrt{2-x}+\sqrt{3x+1}=3\)
\(\Leftrightarrow2x+3+2\sqrt{-3x^2+5x+2}=9\)
\(\Leftrightarrow\sqrt{-3x^2+5x+2}=3-x\)
\(\Leftrightarrow-3x^2+5x+2=x^2-6x+9\)
\(\Leftrightarrow4x^2-11x+7=0\Rightarrow\left[{}\begin{matrix}x=1\\x=\frac{7}{4}\end{matrix}\right.\)