a^3+3a^2-2a-6因式分解

a^3+3a^2-2a-6因式分解

a^3+3a^2-2a-6
=(a^3+3a^2)-(2a+6)
=a²;(a+3)-2(a+3)
=(a+3)(a²;-2)
=(a+3)(a+根號2)(a-根號2)