题目:有13张卡片,如下图。先选出三个数组成一个加法算式,再选出三个数组成一个减法算式,选出的6个数不能重复。怎么组成?【分析与解】从上面这九个数中,先选出三个数组成一个加法算式,再选出三个数组成一个减法算式,有很多种组成方法。以下是三种不同的组法: Title: There are 13 cards, as shown below. First select the three arrays into an addition formula, and then select the three arrays into a subtraction formula, the number of six selected can not be repeated. How to make up? [Analysis and Settlement] From the above nine numbers, the first three selected an array of addition formula, and then select the three arrays into a subtraction formula, there are many ways to form. Here are three different group methods: