Đáp án: $H=-2\sqrt{y}$
Giải thích các bước giải:
Ta có :
$H=\dfrac{(\sqrt{x}+\sqrt{y})^2-4\sqrt{xy}}{\sqrt{x}-\sqrt{y}}-\dfrac{x\sqrt{y}+y\sqrt{x}}{\sqrt{xy}}$
$\to H=\dfrac{x+y+2\sqrt{xy}-4\sqrt{xy}}{\sqrt{x}-\sqrt{y}}-\dfrac{\sqrt{xy}(\sqrt{x}+\sqrt{y})}{\sqrt{xy}}$
$\to H=\dfrac{x+y-2\sqrt{xy}}{\sqrt{x}-\sqrt{y}}-(\sqrt{x}+\sqrt{y})$
$\to H=\dfrac{(\sqrt{x}-\sqrt{y})^2}{\sqrt{x}-\sqrt{y}}-(\sqrt{x}+\sqrt{y})$
$\to H=(\sqrt{x}-\sqrt{y})-(\sqrt{x}+\sqrt{y})$
$\to H=-2\sqrt{y}$
