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计算(能简算的要简算 写出计算过程)(1)53÷45-54×23(2)[447-(345-2

2022-08-14 02:55:03 问答库 阅读 200 次

问题详情

计算(能简算的要简算,写出计算过程)
(1)5

3

÷4

5

-5

4

×2

3


(2)[44

7

-(34

5

-22

3

)×15

7

]÷14

15


(3)129

22

÷61

2

×[24

7

+(24.4-248

45

)]
(4)2+41

6

+61

12

+81

20

+101

30

+121

42


(5)12345678912-1234567890×1234567892
(6)1

3

+1

15

+1

35

+1

63

+…+1

399

参考答案


(1)53÷45-54×23,
=53×54-54×23,
=(53-23)×54,
=1×54,
=54;

(2)[447-(345-223)×157]÷1415,
=[447-(195-83)×157]÷1415,
=[447-(195×157-83×157)]÷1415,
=[327-(577-407)]÷1415,
=[327-177]÷1415,
=157×1514,
=22598;

(3)12922÷612×[247+(24.4-24845)],
=12922÷612×[247+29],
=27322×213×17663,
=163;

(4)2+416+6112+8120+10130+12142,
=(2+4+6+8+10+12)+(16+112+120+130+142)
=(2+12)×6÷2+(12×3+13×4+14×5+15×6+16×7),
=42+(12-13+13-14+14-15+15-16+16-17),
=42+(12-17),
=42+514,
=42514;

(5)12345678912-1234567890×1234567892,
=12345678912-(1234567891-1)(1234567891+1),
=12345678912-(12345678912-1),
=12345678912-12345678912+1,
=1;

(6)13+115+135+163+…+1399,
=11×3+13×5+15×7+17×9+…+119×21,
=12×(1-13+13-15+15-17+17-19+…+119-121),
=12×(1-121),
=12×2021,
=1021.

考点:过程