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-b²)]
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)]
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024