ĐKXĐ: \(x\ge\frac{1}{3}\)
\(x^2+5x=x\sqrt{3x-1}+\left(x+1\right)\sqrt{5x}\)
\(\Leftrightarrow2x^2+10x-2x\sqrt{3x-1}-2\left(x+1\right)\sqrt{5x}=0\)
\(\Leftrightarrow\left(x^2-2x\sqrt{3x-1}+3x-1\right)+\left[\left(x+1\right)^2-2\left(x+1\right)\sqrt{5x}+5x\right]=0\)\(\Leftrightarrow\left(x-\sqrt{3x-1}\right)^2+\left(x+1-\sqrt{5x}\right)^2=0\)
\(\Leftrightarrow\left\{{}\begin{matrix}x-\sqrt{3x-1}=0\\x+1-\sqrt{5x}=0\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=\sqrt{3x-1}\\x+1=\sqrt{5x}\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x^2=3x-1\\\left(x+1\right)^2=5x\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x^2-3x+1=0\\x^2-3x+1=0\end{matrix}\right.\Leftrightarrow x=\frac{3\pm\sqrt{5}}{2}\left(tm\right)\)
