麻烦解几道题

问题描述:

麻烦解几道题
3(a+b)²-27c²a²(a-b)+b²(b-a)(5m²+3n²)²-(3m²+5m²)²
(a²-b²)+(3a-3b)

①3(a+b)²-27c²=3【(a+b)²-(3c)²】=3(a+b-3c)(a+b+3c)②a²(a-b)+b²(b-a)=a²(a-b)-b²(a-b)=(a²-b²)(a-b)=(a-b)(a+b)(a-b)=(a...