`9.`
`P`
`=` $(\sqrt{x}-\frac{x+2}{\sqrt{x}+1}):(\frac{\sqrt{x}}{\sqrt{x}+1}-\frac{\sqrt{x}-4}{1-x})$
`=` $\dfrac{\sqrt{x}(\sqrt{x}+1)-x-2}{\sqrt{x}+1}:(\dfrac{\sqrt{x}}{\sqrt{x}+1}+\dfrac{\sqrt{x}-4}{x-1})$ `=`$\dfrac{\sqrt{x}(\sqrt{x}+1)-x-2}{\sqrt{x}+1}:(\dfrac{\sqrt{x}}{\sqrt{x}+1}+\dfrac{\sqrt{x}-4}{(\sqrt{x}+1)(\sqrt{x}-1)})$
`=` $\dfrac{x+\sqrt{x}-x-2}{\sqrt{x}+1}:\dfrac{\sqrt{x}(\sqrt{x}-1)+\sqrt{x}-4}{(\sqrt{x}+1)(\sqrt{x}-1)}$ `=`$\dfrac{\sqrt{x}-2}{\sqrt{x}+1}:\dfrac{x-\sqrt{x}+\sqrt{x}-4}{(\sqrt{x}+1)(\sqrt{x}-1)}$
`=`$\dfrac{\sqrt{x}-2}{\sqrt{x}+1}:\dfrac{x-4}{(\sqrt{x}+1)(\sqrt{x}-1)}$
`=` $\dfrac{\sqrt{x}-2}{\sqrt{x}+1}:\dfrac{(\sqrt{x}-2)(\sqrt{x}+2)}{(\sqrt{x}+1)(\sqrt{x}-1)}$
`=` $\dfrac{\sqrt{x}-2}{\sqrt{x}+1}.\dfrac{(\sqrt{x}+1)(\sqrt{x}-1)}{(\sqrt{x}-2)(\sqrt{x}+2)}$
`=` $\dfrac{\sqrt{x}-1}{\sqrt{x}+2}$
`@K`
