2/(a²-1)-1/(a²+a) 分式的加减
问题描述:
2/(a²-1)-1/(a²+a) 分式的加减
答
原式=2/(a+1)(a-1)-1/a(a+1)
=2a/a(a+1)(a-1)-(a-1)/a(a+1)(a-1)
=(2a-a+1)/a(a+1)(a-1)
=1/a(a-1)
=1/a²-a