The Member's Method of Solving Problems with Column Equations

Abstract

The correctness and rationality of the set elements in the problem of solving the column equations play an extremely important role in the difficulty of the column equations and the complexity and simplicity of the solution equations. therefore. In order to learn to solve application problems with equations, you must master the method of setting elements well. Considering the relationship between the set element and the required unknown quantity, the set element can be divided into three types: direct set element, indirect set element and partial set element; if considering the number of set elements, the set element can be divided into one set. There are two kinds of yuan and multiple yuan. The following examples are for reference. Example 1 The sum of the number of excavators and the number of loading and unloading trucks at a construction site in a development zone is 21. If each excavator excavates an average of 750m3 of soil per day, and each loading and unloading truck carries an average of 300m3 of soil per day, the excavated soil can be transported away in time. What are the number of door excavators and the number of loading and unloading trucks? (Guangxi 1994 application questions) Solution 1 cannot be used directly. This is what is required in the title to be an unknown element, and a few unknown quantities are required to be set.