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脱式计算(能简便的要用简便方法计算)(1)36+64×85+15(2)0.4×9×25(3)61×40%+38×25+0.4(4)2475÷45+2475÷55(5)(15-14×47)×821(6)157+5.8-87+4.2.

题目详情
脱式计算(能简便的要用简便方法计算)
(1)36+64×85+15    
(2)0.4×9×25    
(3)61×40%+38×
2
5
+0.4
(4)2475÷45+2475÷55 
(5)(15-14×
4
7
)×
8
21
 
(6)
15
7
+5.8-
8
7
+4.2.
▼优质解答
答案和解析
(1)36+64×85+15
=36+5440+15
=5476+15
=5491;

(2)0.4×9×25
=0.4×25×9
=10×9
=90;

(3)61×40%+38×
2
5
+0.4
=61×0.4+38×0.4+0.4
=(61+38+1)×0.4
=100×0.4
=40;

(4)2475÷45+2475÷55
=55+45
=100;

(5)(15-14×
4
7
)×
8
21

=(15-8)×
8
21

=7×
8
21

=
8
3


(6)
15
7
+5.8-
8
7
+4.2
=(
15
7
-
8
7
)+(5.8+4.2)
=1+10
=11.