通分1/a+b,1/a^2-b^2,2/a^-ab
问题描述：
通分1/a+b,1/a^2-b^2,2/a^-ab
答
1/a+b=a(a-b)/[a(a+b)(a-b)]
1/a^2-b^2=a/[a(a+b)(a-b)]
2/a^-ab=2(a+b)/[a(a+b)(a-b)]
答
1/(a+b)=a(a-b)/[a(a+b)(a-b)]=a(a-b)/[a(a²-b²)]=(a²-ab)/[a(a²-b²)]1/(a²-b²)=a/[a(a²-b²)]2/(a²-ab)=2/[a(a-b)]=2(a+b)/[a(a+b)(a-b)]=2(a+b)/[a(a²-b...