(2a-b-c)(2a-b+c)计算
问题描述:
(2a-b-c)(2a-b+c)计算
答
(2a-b-c)(2a-b+c)=[(2a-b)-c][(2a-b)+c]
=(2a-b)2-c2
=4a2-4ab+4b2-c2