Đáp án:
`P=1/(x-1)`
Giải thích các bước giải:
`P=((2sqrtx+x)/(xsqrtx-1)-1/(sqrtx-1)):(1-(sqrtx+2)/(x+sqrtx+1))`
`P=((x+2sqrtx)/((sqrtx-1)(x+sqrtx+1))-(x+sqrtx+1)/((sqrtx-1)(x+sqrtx+1))):((x+sqrtx+1-sqrtx-2)/(x+sqrtx+1))`
`P=((x+2sqrtx-x-sqrtx-1)/((sqrtx-1)(x+sqrtx+1))):(x-1)/(x+sqrtx+1)`
`P=(sqrtx-1)/((sqrtx-1)(x+sqrtx+1))*(x+sqrtx+1)/(x-1)`
`P=1/(x-1)`
`b)x=5+2\sqrt{3}`
`=>P=1/(5+2sqrt3-1)`
`=>P=1/(4+2sqrt3)`
`=>P=(4-2sqrt3)/(16-12)`
`=>P=(4-2sqrt3)/4=(2-sqrt3)/2`