Đáp án:
Giải thích các bước giải:
A=($\frac{ \sqrt[]{x} -2}{x-1}$ -$\frac{\sqrt[]{x} +2}{x+2\sqrt[]{x}+1}$ )($\frac{(x-1)²}{2}$)
= [$\frac{\sqrt[]{x}-2}{y}$ - $ \frac {\sqrt[]{x}+2}{(\sqrt[]{x}+1)²}]$[ $\frac{(x-1)²}{2}$ ]
= [$\frac{\sqrt[]{x}-2}{(\sqrt[]{x}-1)(\sqrt[]{x}+1)}-$ $\frac{(\sqrt[]{x}+2)(\sqrt[]{x}-1)}{(\sqrt[]{x}+1)²}$ ][$\frac{(x-1)²}{2}$ ]
=($\frac{(\sqrt[]{x}-2)(\sqrt[]{x}+1)-(x+\sqrt[]{x}-2)}{(\sqrt[]{x}+1)².(\sqrt[]{x}-1)}$ )($\frac{(x+1)²}{2}$ ) =$\frac{-2\sqrt[]{x}}{(\sqrt[]{x}+1)(\sqrt[]{x}-1}$ )($\frac{(x-1)²}{2}$
= $\sqrt[]{x} $ (1-x)
