hpt cần gấp...............
\left.15\sqrt{5x-y}+22x+4y=15\begin{matrix} \\ \end{matrix}\right\}\sqrt{x-3y}-\sqrt{5x-y}=2
\left.\frac{4xy}{x+y}+\sqrt{x^{2}}-y^{2}=x+y\begin{matrix} \\ \end{matrix}\right\}\sqrt{x+1}-\sqrt{1-y}=\sqrt{1-\frac{1}{x}}
hpt cần gấp...............
\left.15\sqrt{5x-y}+22x+4y=15\begin{matrix} \\ \end{matrix}\right\}\sqrt{x-3y}-\sqrt{5x-y}=2 \left.\frac{4xy}{x+y}+\sqrt{x^{2}}-y^{2}=x+y\begin{matrix} \\ \end{matrix}\right\}\sqrt{x+1}-\sqrt{1-y}=\sqrt{1-\frac{1}{x}}