等于(35.5-5.5)+(12.8+7.2)=30+20=50所以结果等于50
=(35.5-5.5)+(12.8+7.2)=30+20=50
35.5+12.8-5.5+7.2=(35.5-5.5)+(12.8+7.2)=30+20=50希望采纳,谢谢!