纵观各省市历年的中考试题，求代数式值的问题可以说是屡见不鲜．这类问题涉及的知识面较广，尤其是一些重要的基本概念、运算技巧．下面根据各省市历年来中考题中出现的求代数式值的问题归纳出几种常用的求值方法．一、先化简，再来值这种类型题分为两种情形：1．只需化简代数 Looking at the examination questions in various provinces and cities over the years, it can be said that the problem of seeking the value of algebraic numbers is not uncommon. This kind of problem involves a wide range of knowledge, especially some important basic concepts, operation skills. The following is a summary of several commonly used methods for evaluating the algebraic equations that appear in the examination questions of various provinces and cities over the years. First, to simplify, then value this type of problem is divided into two situations: 1. Just simplify algebra