Với `x >= 0,x \ne 4` có:
`M=([x+2]/[\sqrt{x^3}+1]-1/[x-\sqrt{x}+1]):[2-\sqrt{x}]/[x-4\sqrt{x}+4]`
`M=[x+2-\sqrt{x}-1]/[(\sqrt{x}+1)(x-\sqrt{x}+1)].[(\sqrt{x}-2)^2]/[2-\sqrt{x}]`
`M=[x-\sqrt{x}+1]/[(\sqrt{x}+1)(x-\sqrt{x}+1)].[(2-\sqrt{x})^2]/[2-\sqrt{x}]`
`M=1/[\sqrt{x}+1]. (2-\sqrt{x})=[2-\sqrt{x}]/[\sqrt{x}+1]`