题目内容
(a+b)2=______+(a-b)2,(a+b)2+(a-b)2=______.
(a+b)2-(a-b)2
=(a2+2ab+b2)-(a2-2ab+b2)
=4ab;
(a+b)2+(a-b)2
=(a2+2ab+b2)+(a2-2ab+b2)
=2a2+2b2.
故答案是:4ab,2a2+2b2.
=(a2+2ab+b2)-(a2-2ab+b2)
=4ab;
(a+b)2+(a-b)2
=(a2+2ab+b2)+(a2-2ab+b2)
=2a2+2b2.
故答案是:4ab,2a2+2b2.
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