a^+b^ a-b
--- - ---
a^-b^ 2a+2b
參考答案:解:
(a^2+b^2)/(a^2-b^2)-(a-b)/(2a+2b)
=(a^2+b^2)/(a+b)(a-b)-(a-b)/2(a+b)
=2(a^2+b^2)/[2(a+b)(a-b)]-(a-b)^2/[2(a+b)(a-b)]
=[2(a^2+b^2)-(a-b)^2]/[2(a+b)(a-b)]
=[2a^2+2b^2-(a^2-2ab+b^2)]/[2(a+b)(a-b)]
=(a^2+b^2+2ab)/[2(a+b)(a-b)]
=(a+b)^2/[2(a+b)(a-b)]
=(a+b)/2(a-b)
=(a+b)/(2a-2b)
我一步一步来,应该看清楚了吧???