関連ワード:  does a negative plus a negative equal a positive    does a negative times a negative equal a positive    does a negative subtract a negative equal a positive    can a negative plus a negative equal a positive    does a negative plus a negative always equal a positive    can a negative times a negative equal a positive    does a negative times a negative always equal a positive    does a negative number plus a negative number equal a positive    does a negative number times a negative number equal a positive    a negative plus a negative equals a positive movie  
結果 : does a negative plus a negative equal a positive