\(\begin{align}
& \sqrt{x}\left( \sqrt{x}+\sqrt{y} \right)=3\sqrt{y}\left( \sqrt{x}+5\sqrt{y} \right) \\
& x+\sqrt{xy}=3\sqrt{xy}+15y \\
& x-15y=2\sqrt{xy} \\
& {{\left( x-15y \right)}^{2}}={{\left( 2\sqrt{xy} \right)}^{2}} \\
& {{x}^{2}}-34xy+225{{y}^{2}}=0 \\
& x=25y\ or\ 9y \\
\end{align}\)
\(x=9y\)不合
