(x-2y)^2+(x-y)(x-2y)-2(x-3y)(x-y)

原式=(x-2y)(x-2y+x-y)-2(x-3y)(x-y)
=(x-2y)(2x-3y)-2(x-3y)(x-y)
=2x^2-7xy+6y^2-2x^2+8xy-6y^2
=xy

是不是要化简？
(x-2y)^2+(x-y)(x-2y)-2(x-3y)(x-y)
=(x-2y)^2+[(x-2y)-2(x-3y)](x-y)
=(x-2y)^2+(4y-x)(x-y)
=x^2-4xy+4y^2+5xy-4y^2-x^2
=xy

方程吗 还是化简

答案是 XY

想问啥的说？？？