Câu trả lời:
\(3x+3y-10\sqrt{xy}=0\Leftrightarrow\left(3\sqrt{x}-\sqrt{y}\right)\left(\sqrt{x}-3\sqrt{y}\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}3\sqrt{x}=\sqrt{y}\\\sqrt{x}=3\sqrt{y}\end{cases}}\Leftrightarrow\orbr{\begin{cases}y=9x\\x=9y\end{cases}}\)
+TH1: \(y=9x\)
\(M=\frac{x-2.9x}{x+2.9x}=\frac{1-18}{1+18}\)
+TH2: \(x=9y\)
\(M=\frac{9y-2y}{9y+2y}=\frac{9-2}{9+2}\)