在职本科学历:数学题急急急

来源:百度文库 编辑:高校问答 时间:2024/04/30 15:11:52
(x+y/2)^2-(x-y/2)^2

求过程

(x+y/2)^2-(x-y/2)^2
=(x+y/2+x-y/2)(x+y/2-x+y/2) (平方差公式)
=2x*y
=2xy

(x+y/2)^2-(x-y/2)^2

=(x+y/2+x-y/2)x( x+y/2-x+y/2)
=2xy

(x+y/2)^2-(x-y/2)^2
=(x+y/2+x-y/2)(x+y/2-x+y/2) (平方差公式)
=2xy

(x+y/2)^2-(x-y/2)^2
=(x+y/2+x-y/2)(x+y/2-x+y/2) (平方差公式)
=2x*y
=2xy

(x+y/2+x-y/2)*(x+y/2-x+y/2)=2xy