化简﹙x+y+z﹚²-﹙x+y-z﹚²的结果
问题描述:
化简﹙x+y+z﹚²-﹙x+y-z﹚²的结果
答
﹙x+y+z﹚²-﹙x+y-z﹚²
=[﹙x+y+z﹚-﹙x+y-z﹚][﹙x+y+z﹚+﹙x+y-z﹚]
=(2z)(2x+2y)
=4xz+4yz