(x-y)2+______=(x+y)2.-数学

题目简介

(x-y)2+______=(x+y)2.-数学

题目详情

(x-y)2+______=(x+y)2
题型:填空题难度:中档来源:不详

答案

(x+y)2=x2+2xy+y2,
=x2+2xy+y2-4xy+4xy,
=x2-2xy+y2+4xy,
=(x-y)2+4xy,
故(x-y)2+4xy=(x+y)2.

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