Đáp án:
Giải thích các bước giải:
`a,P=((\sqrt{x}+2)/(x-1)-(\sqrt{x}-2)/(x-2\sqrt{x}+1)):(4x)/(x-1)^2(ĐKXĐ:x>=0;xne1)`
`=((\sqrt{x}+2)/[(\sqrt{x}-1)(\sqrt{x}+1)]-(\sqrt{x}-2)/(\sqrt{x}-1)^2):(4x)/(x-1)^2`
`=(((\sqrt{x}+2)(\sqrt{x}-1))/((\sqrt{x}-1)^2(\sqrt{x}+1))-[(\sqrt{x}-2)(\sqrt{x}+1)]/((\sqrt{x}-1)^2(\sqrt{x}+1))):(4x)/(x-1)^2`
`=(((\sqrt{x}+2)(\sqrt{x}-1)-(\sqrt{x}-2)(\sqrt{x}+1)]/((\sqrt{x}-1)^2(\sqrt{x}+1))).(x-1)^2/(4x`
`=((x+\sqrt{x}-2-x+\sqrt{x}+2]/((\sqrt{x}-1)^2(\sqrt{x}+1))).(x-1)^2/(4x`
`=(2\sqrt{x})/((\sqrt{x}-1)^2(\sqrt{x}+1)).((\sqrt{x}-1)^2(\sqrt{x}+1)^2)/(2\sqrt{x})^2`
`=(\sqrt{x}+1)/(2\sqrt{x` `b,|x-5|=4`
`<=>`\(\left[ \begin{array}{l}x-5=4\\x-5=-4\end{array} \right.\)
`<=>`\(\left[ \begin{array}{l}x=9\\x=1\end{array} \right.\)
mà `x>=0;xne1`
`=>x=9`
Thay vào `P` ta dc :
`P=(\sqrt{9}+1)/(2\sqrt{9})=(3+1)/(2.3)=4/6=2/3`
