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计算.(能简算的要用简便方法计算)①25×13×25×310;②79÷115+29×511;③18×58+0.125×41+12.5%;④45÷[58×(1-15)].

题目详情
计算.(能简算的要用简便方法计算)
①25×
1
3
×
2
5
×
3
10
;                
7
9
÷
11
5
+
2
9
×
5
11

1
8
×58+0.125×41+12.5%;        
4
5
÷[
5
8
×( 1-
1
5
)].
▼优质解答
答案和解析
(1)25×
1
3
×
2
5
×
3
10

=(25×
2
5
)×(
1
3
×
3
10

=10×
1
10

=1;

(2)
7
9
÷
11
5
+
2
9
×
5
11

=(
7
9
+
2
9
)×
5
11

=1×
5
11

=
5
11


(3)
1
8
×58+0.125×41+12.5%
=
1
8
×(58+41+1)
=
1
8
×100
=12.5;

(4)
4
5
÷[
5
8
×(1-
1
5
)]
=
4
5
÷[
5
8
×
4
5
]
=
4
5
÷
1
2

=1
3
5