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下面各题 怎样简便就怎样算.39÷7+31×170.625×36+38×36-3649÷[(

2022-08-14 02:23:16 问答库 阅读 200 次

问题详情

下面各题,怎样简便就怎样算.
39÷7+31×1

7


0.625×36+3

8

×36-36

4

9

÷[(5

6

-1

2

)+(5

9

-5

18

)]2008

2009

×2008-2007

1

2

+1

6

+1

12

+1

20

+1

30

+1

42

+1

56

+1

72

(2

9

+5

27

)×27×9.

参考答案

(1)39÷7+31×17
=(39+31)×17
=70×17
=10;

(2)0.625×36+38×36-36,
=(0.625+0.375-1)×36,
=0×36,
=0;

(3)49÷[(56-12)+(59-518)],
=49÷[13+518],
=49÷1118
=811

(4)20082009×2008-2007,
=20082009×2009-20082009×1-2007,
=2008-20082009-2007,
=1-20082009
=12009

(5)12+16+112+120+130+142+156+172
=1-12+12-13+13-14+14-15+15-16+16-17+17-18+18+18-19
=1-19
=89

(6)(29+527)×27×9,
=29×72×9+527×27×9,
=144+45,
=189.

考点: