(a方+3)/(a方-1)-(a+1)/(a-1)+1
问题描述：
(a方+3)/(a方-1)-(a+1)/(a-1)+1
答
(a²+3)/(a²-1)-(a+1)/(a-1)+1=(a²+3)/[(a+1)(a-1)]-(a+1)²/[(a+1)(a-1)]+(a²-1)/[(a+1)(a-1)]=[(a²+3)-(a²+2a+1)+(a²-1)]/[(a+1)(a-1)]=(a²+3-a²-2a-1+a²-1...