分式a+1a−1−a−1a+1的最简公分母是．

Question

分式(a+1)/(a−1)−(a−1)/(a+1)的最简公分母是______．

Answer 1

(a+1)/(a−1)−(a−1)/(a+1)=((a+1)(a+1)−(a−1)(a−1))/((a+1)(a−1))，所以最简公分母是（a+1）（a-1）．