X2y2-x2-y2+1 =x2(y2-1)-(y2-1) =(y2-1)(x2-1) =(y+1)(y-1)(x+1)(x-1) 中的=x2(y2-1)-(y2-1) =(y2-1)(x2-1

分类: 作业答案 • 2022-03-25 15:25:14

问题描述：

X2y2-x2-y2+1 =x2(y2-1)-(y2-1) =(y2-1)(x2-1) =(y+1)(y-1)(x+1)(x-1) 中的=x2(y2-1)-(y2-1) =(y2-1)(x2-1
是怎么算出来的?

答

x2(y2-1)-(y2-1),把y2-1提取,就成=(y2-1)(x2-1）