`#huy`
`(\sqrt{x})/(\sqrt{x}-1)+3/(\sqrt{x}+1)-(6\sqrt{x}-4)/(x-1)`
`=(\sqrt{x}(\sqrt{x}+1)+3(\sqrt{x}-1)-6\sqrt{x}+4)/((\sqrt{x}-1)(\sqrt{x}+1))`
`=(x+\sqrt{x}+3\sqrt{x}-3-6\sqrt{x}+4)/((\sqrt{x}-1)(\sqrt{x}+1))`
`=(x-2\sqrt{x}+1)/((\sqrt{x}-1)(\sqrt{x}+1))`
`=((\sqrt{x}-1)^2)/((\sqrt{x}-1)(\sqrt{x}+1))`
`=(\sqrt{x}-1)/(\sqrt{x}+1)`