工商银行纸黄金价格走势图实时:有1道题怎么写
来源:百度文库 编辑:高考问答 时间:2024/05/29 06:21:08
(1)(3z-2y+1)(3x+2y-1)等于什么
(3z-2y+1)(3x+2y-1)
=[3z-(2y-1)][3x+(2y-1)]
=9z^2-(2y-1)^2
=9z^2-4y^2+4y-1
(3z-2y+1)(3x+2y-1)
=[3z-(2y-1)][3x+(2y-1)]
=9z^2-(2y-1)^2
=9z^2-4y^2+4y-1