`A = ((x sqrtx-1)/(x-sqrtx) - (xsqrtx+1)/(x+sqrtx))/((x+2)(x-2))`.
`= (((sqrtx-1)(x+sqrtx+1))/(sqrtx(sqrtx-1)) - ((sqrtx+1)(x-sqrtx+1))/(sqrtx(sqrtx+1))/((x+2)(x-2))`
`= (x + sqrtx+1)/(sqrtx) - (x - sqrtx+1)/(sqrtx)/((x+2)(x-2))`
`= (2sqrtx)/sqrtx/((x+2)(x-2))`
`= 2/((x+2)(x-2))`.