Tìm a, b sao cho 1/(x + 1)(x - 1) = a/(x + 1) + b/(x - 1)

A. $a = \frac{-1}{2}; b = \frac{-1}{2}$

B. $a = \frac{1}{2}; b = \frac{1}{2}$

C. $a = \frac{1}{2}; b = \frac{-1}{2}$

D. $a = \frac{-1}{2}; b = \frac{1}{2}$