题呢?打出题目来啊
（a-b+(4ab/a-b))×(a+b-(4ab/a+b))
=（a^2-2ab+b^2+4ab)/(a-b)x(a^2+2ab+b^2-4ab)/(a+b)
=((a+b)^2/(a-b))x((a-b)^2/(a+b)
=(a+b)(a-b)
有哪步不懂得?(a^2-2ab+b^2+4ab)/(a-b)x(a^2+2ab+b^2-4ab)/(a+b)看不懂（（a-b)(a-b)/(a-b)+(4ab/a-b))x（（a+b)(a+b)/(a+b)-(4ab/a+b))=(a^2-2ab+b^2+4ab)/(a-b)x(a^2+2ab+b^2-4ab)/(a+b)=(a^2+2ab+b^2+)/(a-b)x(a^2-2ab+b^2)/(a+b) 能看懂不懂了 谢谢