Rút gọn biểu thức P={((x-căn x+2)/((căn x+1)(căn x-2))-(x/(căn x(căn x-2))}/((1- căn x)/(2-căn x))

* Hướng dẫn giải

Ta có:$$\begin{gathered} P=\left[\frac{x-\sqrt{x}+2}{(\sqrt{x}+1)(\sqrt{x}-2)}-\frac{x}{\sqrt{x}(\sqrt{x}-2)}\right]:\frac{1-\sqrt{x}}{2-\sqrt{x}}=\frac{x-\sqrt{x}+2-\sqrt{x}(\sqrt{x}+1)}{(\sqrt{x}+1)(\sqrt{x}-2)}.\frac{2-\sqrt{x}}{1-\sqrt{x}} \\ =\frac{2-2\sqrt{x}}{(\sqrt{x}+1)(\sqrt{x}-1)}=\frac{2(1-\sqrt{x})}{(\sqrt{x}+1)(\sqrt{x}-1)}=-\frac{2}{\sqrt{x}+1} \end{gathered}$$