ĐK: \(12x\ge0\Leftrightarrow x\ge0\)
\(-3-\frac{7}{2}\sqrt{12x}+\frac{5}{2}\sqrt{12x}=-3\sqrt{12x}\\ \Leftrightarrow-\frac{7}{2}\sqrt{12x}+\frac{5}{2}\sqrt{12x}+3\sqrt{12x}=3\\ \Leftrightarrow2\sqrt{12x}=3\\ \Leftrightarrow4\sqrt{3x}=3\\\Leftrightarrow \sqrt{3x}=\frac{3}{4}\\ \Leftrightarrow3x=\frac{9}{16}\\ \Leftrightarrow x=\frac{3}{16}\left(tm\right)\)
Vậy \(x=\frac{3}{16}\)