因式分解 -x²+2xy+y²

问题描述:

因式分解 -x²+2xy+y²
如题

-(x^2-2xy+y^2)+2y^2
=-(x-y)^2+2y^2
=2y^2-(x-y)^2
=(√2y-x+y)(√2y+x-y)