问题 解答题
用递等式计算下面各题:
10÷
5
9
+
1
6
×4

9
20
×
11
25
+
14
25
×
9
20
(15-14×
4
7
)×
8
21
21×(
1
7
+
2
3
答案

(1)10÷

5
9
+
1
6
×4,

=10×

9
5
+
1
6
×4,

=18+

2
3

=18

2
3

(2)

9
20
×
11
25
+
14
25
×
9
20

=

9
20
×(
11
25
+
14
25
),

=

9
20
×1,

=

9
20

(3)(15-14×

4
7
)×
8
21

=(15-8)×

8
21

=7×

8
21

=

8
3

(4)21×(

1
7
+
2
3
),

=21×

1
7
+
2
3
×21,

=3+14,

=17.

单项选择题
单项选择题