问题 解答题
计算下面各题.
2
5
+
5
9
×6)÷
8
15
[
1
4
-(
4
5
-
3
4
)]÷
3
25
1
2
-
1
4
)÷(
1
5
+
1
2
1
2
÷(
1
4
+
3
5
)×
3
5
答案

(1)(

2
5
+
5
9
×6)÷
8
15

=(

2
5
+
10
3
)×
15
8

=(

6
15
+
50
15
)×
15
8

=

56
15
×
15
8

=7;

(2)[

1
4
-(
4
5
-
3
4
)]÷
3
25

=[

1
4
-(
16
20
-
15
20
)]×
25
3

=[

1
4
-
1
20
25
3

=

1
5
×
25
3

=

5
3

(3)(

1
2
-
1
4
)÷(
1
5
+
1
2
),

=

1
4
÷(
2
10
+
5
10
),

=

1
4
×
10
7

=

5
14

(4)

1
2
÷(
1
4
+
3
5
)×
3
5

=

1
2
÷(
5
20
+
12
20
)×
3
5

=

1
2
÷
17
20
×
3
5

=

1
2
×
20
17
×
3
5

=

6
17

名词解释
单项选择题