已知x+y=m求(2x+2y)³-(3x+3y)²的值在线等快速

已知x+y=m求(2x+2y)³-(3x+3y)²的值在线等快速
已知x+y=m求(2x+2y)³-(3x+3y)²的值在线等快速

已知x+y=m求(2x+2y)³-(3x+3y)²的值在线等快速
(2x+2y)³-(3x+3y)²
=8(x+y)^3-9(x+y)^2
=8m^3-9m^2

8m³-9m²

(2x+2y)³-(3x+3y)²
=(2m)^3-(3m)^3
=8m^3-27m^3
=-19m^3

(2x+2y)³-(3x+3y)²=[2(x+y)]³-[3(x+y)]²=(2m)³-(3m)²=8m³-9m²=m²(8m-9)