代数式化简求值是初中数学教学的一个重点和难点内容.学生在解题时如果找不准解决问题的切入点、方法选取不当,往往事倍功半.如何提高学习效率,顺利渡过难关,笔者就这一问题,进行了归类总结并探讨其解法,供同学们参考.一、已知条件不化简,所给代数式化简例1(2004年山西省)先化 The Algebraic Simplified Evaluating is a key and difficult content of mathematics teaching in junior middle school. If students cannot solve the problem when they solve the problem, they will not be able to select the correct method. It is often less effective. How to improve the learning efficiency and overcome the difficulties smoothly? This question was categorized and summed up to discuss its solution for the students to refer to. First, the known conditions are not simplified, given the Algebraic Simplified Example 1 (in Shanxi Province in 2004)