分解因式7x2-2xy-3y2 a2+(a+1)2+a2(a+1)2 x2-xy+2x+y-3

分类: 作业答案 • 2022-01-02 12:49:21

问题描述：

答

7x2-2xy-3y2 =7(x-y/7+根号22y/7)(x-y/7-根号22y/7)
a2+(a+1)2+a2(a+1)2=2(a2+a)+1+(a2+a)2=(a2+a+1)2
x2-xy+2x+y-3=(x2+2x-3)-(xy-y)=(x-1)(x+3-y)