(a+b)^2-(a-b)^2-4ab
=[(a+b)+(a-b)]*[(a+b)-(a-b)]-4ab
=2a*2b-4ab
=4ab-4ab
=0
呵呵,做错了不怪我肢局,
做对了,告卜来抱一个,开香摈庆祝
话说,我上初中那会儿,计算可不怎么样历友让啊。最悲壮的那次1+2我等于4
原式=(a+b+a-b)(a+b-a+b)-4ab
=(2a)(2b)-4ab
=4ab-4ab
=0
(返芦团漏橘哗答a+b)^2-(a-b)^2-4ab
=a^2+2ab+b^2-a^2+2ab-b^2-4ab
=a^2-a^2+b^2-b^2+2ab+2ab-4ab
=0