原式=2(x-y)^2+3-(x-y)
=2(x-y)^2-3(y-x)
=2(y-x)^2-3(y-x)
=(y-x)(2-3(y-x))
=(y-x)(2-3y+3x)
有时候要加负号哦!然后提取公因式!
明白了吗?