関連ワード:  is a negative plus a negative a positive number    is a negative times a negative a positive number    does a negative plus a negative equal a positive number    is a negative number times a negative number equal a positive number    why does a negative times a negative equal a positive number    does a negative number times a negative number make a positive number    does a negative number plus a negative number make a positive    is a positive plus a negative a negative    is a negative plus a negative always a positive    does a negative plus a positive equal a negative  
結果 : is a negative plus a negative a positive number