(x+2y)²-2(x-y)(x-y)+2y(x-3y)帮忙化简下,准确一点哦,

问题描述:

(x+2y)²-2(x-y)(x-y)+2y(x-3y)帮忙化简下,准确一点哦,

=x²-4xy+4y²-2(x-y)²+2xy-6y²=x²-4xy+4y²-2(x²-2xy+y²)+2xy-6y²=x²-4xy+4y²-2x²+4xy-2y²+2xy-6y²=-x²+2xy-4y²