Đáp án + Giải thích các bước giải:
`(\sqrtx+1)/(\sqrtx-1)+(\sqrtx-1)/(\sqrtx+1)-(3\sqrtx+1)/(x-1)(x\ne1;x\ge0)`
`=(\sqrtx+1)^2/(x-1)+(\sqrtx-1)^2/(x-1)-(3\sqrtx+1)/(x-1)`
`=(x+2\sqrtx+1+x-2\sqrtx+1-3\sqrtx-1)/(x-1)`
`=(2x-3\sqrtx+1)/(x-1)`
`=(2x-2\sqrtx-\sqrtx+1)/(x-1)`
`=(2\sqrtx(\sqrtx-1)-(\sqrtx-1))/(x-1)`
`=((\sqrtx-1)(2\sqrtx-1))/((\sqrtx-1)(\sqrtx+1))`
`=(2\sqrtx-1)/(\sqrtx+1)`