问题 解答题
用递等式计算
4
7
×
21
10
×
2
5
3
5
×
2
9
×15
15÷
9
10
×
3
5
5
12
÷
5
9
5
8
÷
7
12
÷
7
10
1
2
÷
5
4
×
2
3
答案

(1)

4
7
×
21
10
×
2
5

=

6
5
×
2
5

=

12
25

(2)

3
5
×
2
9
×15,

=

2
15
×15,

=2;

(3)15÷

9
10
×
3
5

=15×

10
9
×
3
5

=

50
3
×
3
5

=10;

(4)4×

5
12
÷
5
9

=

5
3
×
9
5

=3;

(5)

5
8
÷
7
12
÷
7
10

=

5
8
×
12
7
×
10
7

=

15
14
×
10
7

=1

26
49

(6)

1
2
÷
5
4
×
2
3

=

1
2
×
4
5
×
2
3

=

2
5
×
2
3

=

4
15

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