一、“设而不求”在代数式求值中的应用代数式主要包括整式、分式和根式.代数式求值是初中数学常见题型之一,大部分代数式求值较为简单,只需按照代数式的运算法则直接运算即可,但是,也有部分代数式的求值运用一般方法很难解决,需要特定的解题方法和技巧. First, the “algebraic expression ” in the evaluation of algebraic algebraic type mainly includes the whole, fractional and root algebraic evaluation is one of the common problems in junior high school mathematics, most of the algebraic evaluation is relatively simple, just follow the Algebraic algorithms are straightforward, but there are some algebraic evaluations that are hard to solve using general methods that require specific problem-solving techniques and techniques.