Đáp án:
1 ,
$\dfrac{(x-\sqrt{x})(\sqrt{x} + 1)}{(\sqrt{x} - 1)(\sqrt{x} + 1)}$
`=` $\dfrac{x\sqrt{x} - x + x - \sqrt{x}}{x - 1}$
`=` $\dfrac{\sqrt{x}( x - 1 )}{x-1}$ `=` $\sqrt{x}$
2,
$\dfrac{x\sqrt{x} - 2x}{2 - \sqrt{x}}$ `=` $\dfrac{\sqrt{x}-2}{2 - \sqrt{x}}$ `=` `-``x`