`(3\sqrt{x}-1)/(\sqrt{x}-3)`
Ta có:
`5-2\sqrt{6}`
`=3-2\sqrt{6}+2`
`=(\sqrt{3})^2-2*\sqrt{3}*\sqrt{2}+(\sqrt{2})^2`
`=(\sqrt{3}-\sqrt{2})^2`
Thay `x=(\sqrt{3}-\sqrt{2})^2`
`(3*\sqrt{(\sqrt{3}-\sqrt{2})^2}-1)/(\sqrt{(\sqrt{3}-\sqrt{2})^2}-3)`
`=(3(\sqrt{3}-\sqrt{2})-1)/(\sqrt{3}-\sqrt{2}-3)`
`=(3\sqrt{3}-\sqrt{6}-1)/(\sqrt{3}-\sqrt{2}-3)`