计算(2x-3y)(x+4y)-(3x+y)(x-2y)(2x-3y)(x+4y)-(3x+y)(x-2y)

问题描述:

计算(2x-3y)(x+4y)-(3x+y)(x-2y)
(2x-3y)(x+4y)-(3x+y)(x-2y)

原式=(2x²+8xy-3xy-12y²)-(3x²-6xy+xy-2y²)
=2x²+8xy-3xy-12y²-3x²+6xy-xy+2y²
=-x²+10xy-10y²