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(2012•哈尔滨模拟)计算,能简算的要简算:57÷(5−3×23);85×14+0.25×15;24×(23−12+14);5.9×10112÷[(23−25)×710];(1−14−512)÷23.

题目详情
(2012•哈尔滨模拟)
计算,能简算的要简算:
5
7
÷(5−3×
2
3
);
85×
1
4
+0.25×15;
24×(
2
3
1
2
+
1
4
);
5.9×101                            
1
2
÷[(
2
3
2
5
7
10
];
(1−
1
4
5
12
2
3
▼优质解答
答案和解析
(1)
5
7
÷(5-3×
2
3
),
=
5
7
÷(5-2),
=
5
7
÷3,
=
5
21


(2)85×
1
4
+0.25×15,
=0.25×(85+15),
=0.85×100,
=85;

(3)24×(
2
3
1
2
+
1
4
),
=24×
2
3
-24×
1
2
+24×
1
4

=16-12+6,
=4+6,
=10;

(4)5.9×101,
=5.9×(100+1),
=5.9×100+5.9×1,
=590+5.9,
=595.9;

(5)
1
2
÷[(
2
3
2
5
)×
7
10
],
=1
1
2
÷[
4
15
×
7
10
],
=
1
2
÷
14
75

=2
19
28


(6)(1-
1
4
-
5
12
÷
2
3

=(
3
4
5
12
÷
2
3

=
1
3
÷
2
3

=0.5.