(x-3y)(y+2x)-(4y-3x)(3x+4y)计算
问题描述:
(x-3y)(y+2x)-(4y-3x)(3x+4y)计算
答
(x-3y)(y+2x)-(4y-3x)(3x+4y)
=2x^2-3y^2-5xy+9x^2-16y^2
=11x^2-5xy-19y^2