a+2b=0 , 求a^3+3a^2 × b+2ab^2的值

问题描述:

a+2b=0 , 求a^3+3a^2 × b+2ab^2的值

a^3+3a^2 × b+2ab^2
=a(a²+3ab+2b²)
=a(a+2b)(a+b)
=0