$\begin{cases}(14-3x)\sqrt{4-x}=(3y+11)\sqrt{3+y} (1) \\ \sqrt[3]{x+6}+2\sqrt{3-y}=6 (2) \end{cases}$ $(1) \Leftrightarrow 2\sqrt{4-x}+3(4-x)\sqrt{4-x}=2\sqrt{3+y} +3(3+y)\sqrt{3+y}\Rightarrow 4-x=3+y$$(2) \Leftrightarrow \sqrt[3]{x+6}+2\sqrt{x+2}=6$$\Leftrightarrow x=2 \vee \frac{1}{\sqrt[3]{x+6}^{2}+2\sqrt[3]{x+6}+4}=\frac{1}{\sqrt{x+2}+2}$ (vô nghiệm)
$\begin{cases}(14-3x)\sqrt{4-x}=(3y+11)\sqrt{3+y} (1) \\ \sqrt[3]{x+6}+2\sqrt{3-y}=6 (2) \end{cases}$ $(1) \Leftrightarrow 2\sqrt{4-x}+3(4-x)\sqrt{4-x}=2\sqrt{3+y} +3(3+y)\sqrt{3+y}\Rightarrow 4-x=3+y$$(2) \Leftrightarrow \sqrt[3]{x+6}+2\sqrt{x+2}=6$$\Leftrightarrow x=2 \vee \frac{1}{\sqrt[3]{x+6}^{2}+2\sqrt[3]{x+6}+4}=\frac{2}{\sqrt{x+2}+2}$ (vô nghiệm)