a立方减a减6 怎么分解因式?
问题描述:
a立方减a减6 怎么分解因式?
帮帮芒
答
a^3-a-6
=a^3-4a+3a-6
=a(a^2-4)+3(a-2)
=a(a+2)(a-2)+3(a-2)
=(a-2)(a^2+2a+3)