`***`Lời giải`***`
a)
`Q=\frac{3x-3\sqrt{x}-3}{x+\sqrt{x}-2}-\frac{\sqrt{x}+1}{\sqrt{x}+2}-\frac{\sqrt{x}-2}{\sqrt{x}-1} `
ĐKXĐ: `x≥0;xne1`
`=\frac{3x-3\sqrt{x}-3}{x-\sqrt{x}+2\sqrt{x}-2}-\frac{\sqrt{x}+1}{\sqrt{x}+2}-\frac{\sqrt{x}-2}{\sqrt{x}-1} `
`=\frac{3x-3\sqrt{x}-3}{\sqrt{x}(\sqrt{x}-1)+2(\sqrt{x}-1)}-\frac{\sqrt{x}+1}{\sqrt{x}+2}-\frac{\sqrt{x}-2}{\sqrt{x}-1} `
`=\frac{3x-3\sqrt{x}-3}{(\sqrt{x}-1)(\sqrt{x}+2)}-\frac{\sqrt{x}+1}{\sqrt{x}+2}-\frac{\sqrt{x}-2}{\sqrt{x}-1} ``=\frac{3x-3\sqrt{x}-3-(\sqrt{x}+1)(\sqrt{x}-1)-(\sqrt{x}-2)(\sqrt{x}+2)}{(\sqrt{x}-1)(\sqrt{x}+2)} `
`=\frac{3x-3\sqrt{x}-3-(x-1)-(x-4)}{(\sqrt{x}-1)(\sqrt{x}+2)} `
`=\frac{3x-3\sqrt{x}-3-x+1-x+4}{(\sqrt{x}-1)(\sqrt{x}+2)} `
`=\frac{x-3\sqrt{x}+2}{(\sqrt{x}-1)(\sqrt{x}+2)} `
`=\frac{x-\sqrt{x}-2\sqrt{x}+2}{(\sqrt{x}-1)(\sqrt{x}+2)} `
`=\frac{\sqrt{x}(\sqrt{x}-1)-2(\sqrt{x}-1)}{(\sqrt{x}-1)(\sqrt{x}+2)} `
`=\frac{(\sqrt{x}-2)(\sqrt{x}-1)}{(\sqrt{x}-1)(\sqrt{x}+2)} `
`=\frac{\sqrt{x}-2}{\sqrt{x}+2} `
Vậy `Q=\frac{\sqrt{x}-2}{\sqrt{x}+2} ` với `x≥0;xne1`
