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16-47 28-(-74)

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/16 08:21:03
16-47 28-(-74)
(3.8)-(+7) (-5.9)—(6.1)
(+2/5)-(-3/5)   (-2/5)—(-3/5)
 1/2-1/3        (-1/2)-1/3
 -4.2+5.7-8.4+10   -1/4+5/6+2/3+1/2
 12-(-18)+(-7)-15     4.7-(8.9)-7.5+(-6)
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16-47=-(47-16)=-31 28-(-74)=28+72+2=100+2=102
(3.8)-(+7)=-(7-3.8)=-3.2 (-5.9)—(6.1)=-(5.9+6.1)=-12
(+2/5)-(-3/5)=2/5+3/5=5/5=1   (-2/5)—(-3/5)=3/5-2/5=1/5
 1/2-1/3=3/6-2/6=1/6        (-1/2)-1/3=-(3/+2/6)=-5/6
 -4.2+5.7-8.4+10=-(4.2+8.4)+15.7=15.7-12.6=3.1
-1/4+5/6+2/3+1/2=-1/4+5/6+4/6+3/6=-1/4+12/6=2-1/4=8/4-1/4=7/4
 12-(-18)+(-7)-15=12+18-(7+15)=30-22=8     
4.7-(8.9)-7.5+(-6)=4.7-(8.9+7.5+6)=4.7-(15.4+6)=-(21.4-4.7)=-16.7