Với `x >= 0,x \ne 1` có:
`([2\sqrt{x}+x]/[x\sqrt{x}-1]+\sqrt{x}/[\sqrt{x}-1]):[\sqrt{x}+2]/[x+\sqrt{x}+1]`
`=[2\sqrt{x}+x+\sqrt{x}(x+\sqrt{x}+1)]/[(\sqrt{x}-1)(x+\sqrt{x}+1)].[x+\sqrt{x}+1]/[\sqrt{x}+2]`
`=[2\sqrt{x}+x+x\sqrt{x}+x+\sqrt{x}]/[(\sqrt{x}-1)(\sqrt{x}+2)]`
`=[x\sqrt{x}+2x+3\sqrt{x}]/[(\sqrt{x}-1)(\sqrt{x}+2)]`