问题 解答题
计算下列各题.
2
5
×
4
7
×
21
10

3
4
×
8
15
×
10
13

16
9
×4×
3
4
答案

(1)

2
5
×
4
7
×
21
10

=

2
5
×(
4
7
×
21
10

=

2
5
×
6
5

=

12
25

(2)

3
4
×
8
15
×
10
13

=

2
5
×
10
13

=

4
13

(3)

16
9
×4×
3
4

=

16
9
×(4×
3
4

=

16
9
×3

=5

1
3

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