(-2ab)的平方(3a的平方-ab-4b的平方)计算还有几题(x-y)的平方-y(x+y0(2a+b-3)(2a+b+3)
问题描述:
(-2ab)的平方(3a的平方-ab-4b的平方)计算
还有几题
(x-y)的平方-y(x+y0
(2a+b-3)(2a+b+3)
答
(-2ab)2 (3a2 -ab-4b2) =4a2b2 (3a2 -ab-4b2) 4a2b2 (3a-4b)(a+b) (x-y)2-y(x+y) = (x+y)(x-y)-y(x+y) =(x+y)[(x-y)-y] = (x+y)× (x-2y) (2a+...