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计算下列各题,能简算的要简算.(1)12.5×3.2×25(2)379−1.16−1.84+129(3)(38+34−12)÷24(4)49×[34−(710−14)](5)19-19×1920(6)(8-10×45)÷13÷13.

题目详情
计算下列各题,能简算的要简算.
(1)12.5×3.2×25 (2)3
7
9
−1.16−1.84+1
2
9
(3)(
3
8
+
3
4
1
2
)÷24
(4)
4
9
×[
3
4
−(
7
10
1
4
)]
(5)19-19×
19
20
(6)(8-10×
4
5
1
3
÷
1
3
▼优质解答
答案和解析
(1)12.5×3.2×25,
=12.5×0.8×4×25,
=(12.5×0.8)×(4×25),
=10×100,
=1000;

(2)3
7
9
−1.16−1.84+1
2
9

=(3
7
9
+1
2
9
)-(1.16+1.84),
=5-3,
=2;

(3)(
3
8
+
3
4
1
2
)÷24,
=(
9
8
-
1
2
)÷24,
=
5
8
÷24,
=
5
192


(4)
4
9
×[
3
4
−(
7
10
1
4
)],
=
4
9
×[
3
4
+
1
4
-
7
10
],
=
4
9
×(1-
7
10
),
=
4
9
×
3
10

=
2
15


(5)19-19×
19
20

=19×1-19×
19
20

=19×(1-
19
20
),
=19×
1
20

=
19
20


(6)(8-10×
4
5
÷
1
3

=(8-8)÷
1
3

=0÷
1
3

=0.