一、知识背景我们知道,列出一元一次方程解应用题的方法是:1.弄清题意和题目中的数量关系,用字母(如x)表示题中的一个未知数;2.找出能够表示应用题全部含义的一个相等关系;3.根据这个相等关系列出需要代数式,从而列出方程;4.解这个方程,求出未知数的值; First, the knowledge background We know that the list of unary equations to solve problems in the application of the method is: 1. To clarify the meaning of the title and the number of questions in the title, using letters (such as x) to indicate an unknown in the title; 2. Find out An equal relationship representing the full meaning of the problem; 3. List algebraic equations based on this equivalence to list the equations; 4. Solve the equation and find the value of the unknown;