懂数学的求点拨,怎样由x²+xy-2y²=0得到=(2x-y)(x-y)求解
问题描述:
懂数学的求点拨,怎样由x²+xy-2y²=0得到=(2x-y)(x-y)求解
怎样由x²+xy-2y²=0得到=(2x-y)(x-y)=0求解
答
解x²+xy-2y²=0
(x²-y²)+(xy-y²)=0
(x+y)(x-y)+y(x-y)=0
(x-y)(x+y+y)=0
(x-y)(x+2y)=0
所以x-y=0 x=y
或者x+2y=0 x=﹣2y