计算:(2x+y+z)(2x-y-1)
问题描述：
计算:(2x+y+z)(2x-y-1)
打错了是(2x+y+1)(2x-y-1)
答
=（2x+（y+1））（2x-（y+1））=（2x)^2-(y+1)^2=4x^2-y^2-2y-1
计算:(2x+y+z)(2x-y-1)
打错了是(2x+y+1)(2x-y-1)
=（2x+（y+1））（2x-（y+1））=（2x)^2-(y+1)^2=4x^2-y^2-2y-1