（a＋b＋c）^n展开式系数规律的研究

Research about Regularity of Trinomial Expansion Coefficient

本文给出了反映三项展开式系数规律的类似'杨辉三角'的三角形数表,并给出了写出三项展开式的一般步骤,利用这个三角形数表以及文中的方法可以简便快速地写出(a+b+c)n的展开式.

This article gives out triangle number tables similar to 'YangHui Triangle' , which reflects the regularity of trinomial expansion coefficient . It also gives out the general steps to expend trinomials . By using this triangle number table and the method in this article, you can expend a trinomial easily and quickly .