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(2009•承德县模拟)计算,能简算的要简算.(4-7.5×415)÷1190.25÷523+0.25×5252.8×27+1.2÷7245÷[72×(34−13)]7.2+[(7.8+15)÷0.4]65−27+45−57.

题目详情
(2009•承德县模拟)
计算,能简算的要简算.
(4-7.5×
4
15
)÷
11
9
0.25÷
5
23
+0.25×5
2
5
2.8×
2
7
+1.2÷
7
2
45÷[72×(
3
4
1
3
)]
7.2+[(7.8+
1
5
)÷0.4]
6
5
2
7
+
4
5
5
7
▼优质解答
答案和解析
(1)(4-7.5×
4
15
)÷
11
9

=(4-2)÷
11
9

=2×
9
11

=
18
11


(2)0.25÷
5
23
+0.25×5
2
5

=0.25×
23
5
+0.25×
27
5

=0.25×(
23
5
+
27
5
),
=0.25×10,
=2.5;

(3)2.8×
2
7
+1.2÷
7
2

=2.8×
2
7
+1.2×
2
7

=(2.8+1.2)×
2
7

=4×
2
7

=
8
7


(4)45÷[72×(
3
4
1
3
)],
=45÷[72×
5
12
],
=45÷30,
=1.5;

(5)7.2+[(7.8+
1
5
)÷0.4],
=7.2+[8÷0.4],
=7.2+20,
=27.2;

(6)
6
5
2
7
+
4
5
5
7

=(
6
5
+
4
5
)-(
2
7
+
5
7
),
=2-1,
=1.