`***`Lời giải`***`
`P=(\sqrt{x}-\frac{x+2}{\sqrt{x}+1}):(\frac{\sqrt{x}}{\sqrt{x}+1}-\frac{\sqrt{x}-4}{1-x}) `
ĐKXĐ: `x≥0;xne1;xne4`
`=\frac{\sqrt{x}(\sqrt{x}+1)-(x+2)}{\sqrt{x}+1}:(\frac{\sqrt{x}}{\sqrt{x}+1}+\frac{\sqrt{x}-4}{x-1}) `
`=\frac{\sqrt{x}(\sqrt{x}+1)-(x+2)}{\sqrt{x}+1}:\frac{\sqrt{x}(\sqrt{x}-1)+\sqrt{x}-4}{x-1} `
`=\frac{x+\sqrt{x}-x-2}{\sqrt{x}+1}:\frac{x-\sqrt{x}+\sqrt{x}-4}{x-1} `
`=\frac{\sqrt{x}-2}{\sqrt{x}+1}:\frac{x-4}{x-1} `
`=\frac{\sqrt{x}-2}{\sqrt{x}+1}.\frac{x-1}{ x-4 } `
`=\frac{\sqrt{x}-2}{\sqrt{x}+1}.\frac{(\sqrt{x}-1)(\sqrt{x}+1)}{(\sqrt{x}-2)(\sqrt{x}+2) } `
`=\frac{\sqrt{x}-1}{\sqrt{x}+2} `
Vậy `P=\frac{\sqrt{x}-1}{\sqrt{x}+2} ` với `x≥0;xne1;xne4`
