$\dfrac{1}{\sqrt{x-1}-\sqrt{x}}+\dfrac{1}{\sqrt{x-1}+\sqrt{x}}+\dfrac{\sqrt{x³}-x}{\sqrt{x}-1}$ `Đk: x≥1;x≥0`
$=\dfrac{\sqrt{x-1}+\sqrt{x}+\sqrt{x-1}-\sqrt{x}}{\sqrt{x-1}²-\sqrt{x}²}+\dfrac{x(\sqrt{x}-1)}{\sqrt{x}-1}$
$=\dfrac{2\sqrt{x-1}}{x-1-x}+x$
$=-2\sqrt{x-1}+x$