Câu 1:
\(\Rightarrow\left\{{}\begin{matrix}\left(\sqrt{x}+\sqrt{y}\right)^2=4^2\\\sqrt{xy}=3\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x+y=10\\xy=9\end{matrix}\right.\\ \)
\(M=x^2+y^2=\left(x+y\right)^2-2xy...\)
Câu 2:
\(\Rightarrow x+y+2\sqrt{xy}=16\\ \Leftrightarrow\left(\sqrt{x}+\sqrt{y}\right)^2=16\\ \Rightarrow\sqrt{x}+\sqrt{y}=4\)
\(M=x\sqrt{x}+y\sqrt{y}=\left(\sqrt{x}+\sqrt{y}\right)\left(x-\sqrt{xy}+y\right)...\)