Đáp án+Giải thích các bước giải:
Với `x≥0;x\ne25`
`B=((15-\sqrtx)/(x-25)+2/(\sqrtx+5)):(\sqrtx+1)/(\sqrtx-5)`
`=((15-\sqrtx)/((\sqrtx-5)(\sqrtx+5))+2/(\sqrtx+5)):(\sqrtx+1)/(\sqrtx-5)`
`=(15-\sqrtx+2(\sqrtx-5))/((\sqrtx-5)(\sqrtx+5)):(\sqrtx+1)/(\sqrtx-5)`
`=(15-\sqrtx+2\sqrtx-10)/((\sqrtx-5)(\sqrtx+5)).(\sqrtx-5)/(\sqrtx+1)`
`=(\sqrtx+5)/(\sqrtx+5).(1)/(\sqrtx+1)`
`=1/(\sqrtx+1)`
Vậy với `x≥0;x\ne25` thì `B=1/(\sqrtx+1)`
