因式分解a^3-3a^2-4a
问题描述：
因式分解a^3-3a^2-4a
答
a^3-3a^2-4a
=a(a^2-3a-4)
a(a-4)(a+1)
答
=a(a^2-3a-4)
=a(a-4)(a+1)
答
a^3-3a^2-4a=a(a^2-3a-4)=a(a-4)(a+1)