Đáp án + Giải thích các bước giải:
`a)` ` ĐKXĐ:x≥0;x\ne4`
`P=(\sqrt{x}+1)/(\sqrt{x}-2)+(2\sqrt{x})/(\sqrt{x}+2)+(2+5\sqrt{x})/(4-x)`
`=(\sqrt{x}+1)/(\sqrt{x}-2)+(2\sqrt{x})/(\sqrt{x}+2)-(2+5\sqrt{x})/(x-4)`
`=((\sqrt{x}+1)(\sqrt{x}+2)+2\sqrt{x}(\sqrt{x}-2)-(2+5\sqrt{x}))/((\sqrt{x}-2)(\sqrt{x}+2))`
`=(x+\sqrt{x}+2\sqrt{x}+2+2x-4\sqrt{x}-2-5\sqrt{x})/((\sqrt{x}-2)(\sqrt{x}+2))`
`=(3x-6\sqrt{x})/((\sqrt{x}-2)(\sqrt{x}+2))`
`=(3\sqrt{x}(\sqrt{x}-2))/((\sqrt{x}-2)(\sqrt{x}+2))`
`=(3\sqrt{x})/(\sqrt{x}+2)`
`b)`
`P=2`
`<=>(3\sqrt{x})/(\sqrt{x}+2)=2`
`<=>3\sqrt{x}=2(\sqrt{x}+2)`
`<=>3\sqrt{x}=2\sqrt{x}+4`
`<=>3\sqrt{x}-2\sqrt{x}=4`
`<=>\sqrt{x}=4`
`<=>x=16\ (tmđk)`
