numbers from 1 to 9 are used to form three formulas.eachn number can only be used for once.and only plus sign and multip
问题描述：
numbers from 1 to 9 are used to form three formulas.eachn number can only be used for once.and only plus sign and multiple sing can be used.please write down the three formulas.求求大家了.
答
用1到9的数字用来组成三个通式.每个数字只能用一次,只可以使用加号和乘号,请写下三个通式.