常值换元是一种“反客为主”的换元形式,它常常将数学问题中的某一个已知数用字母代替作为辅助元,把看似复杂的数学问题转化为结构简单的数学问题,实现化繁为简,化未知为已知,达到解题目的.下面结合实例介绍 Constant value change is a “anti-dominated ” substitution form, it often will be a mathematical problem in a known number instead of using letters as auxiliary elements, the seemingly complex mathematical problem into a simple mathematical problem , The realization of complex to simplify, unknown as known, to solve the problem. The following combination of examples introduced