Đáp án + Giải thích các bước giải:

`B = ( sqrtx/(x + 2sqrtx) + sqrtx/(2 - sqrtx) + (2x - sqrtx + 2)/(x - 4)) . (x + 3)/sqrtx`

`B = (sqrtx/(sqrtx(sqrtx + 2)) + sqrtx/(2 - sqrtx)+(2x - sqrtx + 2)/(x - 4)) . (x + 3)/sqrtx`

`B = ( 1/(sqrtx + 2) - sqrtx/(sqrtx - 2) + (2x - sqrtx + 2)/((sqrtx - 2)(sqrtx+ 2)) ) . (x + 3)/sqrtx`

`B = ((sqrtx - 2)/((sqrtx - 2)(sqrtx+ 2)) - (sqrtx(sqrtx + 2))/((sqrtx - 2)(sqrtx+ 2)) + (2x - sqrtx + 2)/((sqrtx - 2)(sqrtx+ 2)) ) . (x + 3)/sqrtx`

`B = (sqrtx - 2 - x - 2sqrtx + 2x - sqrtx + 2)/((sqrtx - 2)(sqrtx+ 2)) . (x + 3)/sqrtx`

`B = (-2sqrtx + x)/((sqrtx - 2)(sqrtx+ 2)) . (x + 3)/sqrtx`

`B = (sqrtx(-2 + sqrtx))/((sqrtx - 2)(sqrtx+ 2)) . (x + 3)/(sqrtx)`

`B = (sqrtx)/(sqrtx + 2) . (x + 3)/sqrtx`

`B = (x + 3)/(sqrtx + 2)`