`B = ((x+2)/(xsqrt(x) - 1) + (sqrt(x))/(x+sqrt(x) + 1) - 1/(sqrt(x) - 1) : (sqrt(x) - 1)/2 (x >= 0, xne 1)`

`B = [(x+2)/((sqrt(x) - 1)(x+sqrt(x) + 1)) + (sqrt(x) . (sqrt(x) - 1))/((sqrt(x) - 1)(x+sqrt(x) + 1)) - (x+sqrt(x) + 1)/((sqrt(x) - 1)(x+sqrt(x) + 1))] . 2/(sqrt(x) - 1)`

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

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

`B = (x - 2sqrt(x) + 1)/((sqrt(x) - 1)^2 . (x+sqrt(x) + 1)) . 2`

`B = (2(sqrt(x) - 1)^2)/((sqrt(x) - 1)^2 . (x+sqrt(x) + 1))`

`B = 2/(x+sqrt(x) + 1)`

Vậy, `B = 2/(x+sqrt(x) + 1)` với `x >= 0, x ne 1`.