\(1A=\frac{x+\sqrt{xy}}{\sqrt{x}+\sqrt{y}}-\frac{x-y}{\sqrt{x}-\sqrt{y}}=\frac{\sqrt{x}\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{x}+\sqrt{y}}-\frac{\left(\sqrt{x}+\sqrt{y}\right)\left(\sqrt{x}-\sqrt{y}\right)}{\sqrt{x}-\sqrt{y}}\)
\(=1\sqrt{x}-\sqrt{x}-\sqrt{y}=-\sqrt{y}\)