去括号,交换项的位置
=52.17-34.9-12.17
=52.17-12.17-34.9
=40-34-0.9
=6-0.9
=5.1
无上二点一七减去括号三四点九再减去十二点无上二点一七减去括号三四点九再减去十二点一七的简便方法52.17减去括号34.9,再减去12.17的简便方法就是先把第一个是52.17减去括号34.9,再减去12.17的简便方法就是先把第一个数和12.17减。然后再去减34.9。结果等于5.1。
52.17-(34.9+12.17)
=52.17-12.17-34.9
=40-34.9
=5.1
简便方法:减法性质
52.17-(34.9+12.17)=52.17-12.17-35+0.1=40-35+0.1=5.1
52.17-(34.9+12.17)
=52.17-12.17-34.9
=40-34.9
=5.1