“+”号说:我有时叫加号,有时也叫正号,有时叫加号正号都行.例如,(-2)+(+5)第一个“+”号是加号,第二个“+”号是正号;又如:-2+5式子中的“+”号可以理解为加(负2加上5的和),也可理解为正号(负2与正5的和,加号省),使用我时通常可省略,特别是当算式的第一个数是正号时这个正号可省略不写,当求几个数的代 The “+” says: I sometimes call the plus sign, sometimes it’s called the positive sign, sometimes it’s called the positive plus sign. Both, for example, (-2) + (+5) The first “+” sign is the plus sign. Two “+” signs are positive signs; another example: the “+” sign in the -2+5 expression can be interpreted as plus (sum of plus 2 plus 5), and can also be interpreted as plus sign (negative 2 and plus 5). The sum of, plus the province), usually can be omitted when using me, especially when the first number of the formula is a positive number, this positive number can be omitted and written, when the number of generations