问题 解答题
脱式计算.
(1)
1
3
÷(
2
3
-
2
5
)×
3
5

(2)
1
2
-(
3
4
-
3
5
)÷
7
10

(3)
7
9
÷
11
5
+
2
9
×
5
11
答案

(1)

1
3
÷(
2
3
-
2
5
)×
3
5

=

1
3
÷
4
15
×
3
5

=

5
4
×
3
5

=

3
4

(2)

1
2
-(
3
4
-
3
5
)÷
7
10

=

1
2
-
3
20
÷
7
10

=

1
2
-
3
14

=

2
7

(3)

7
9
÷
11
5
+
2
9
×
5
11

=(

7
9
+
2
9
)×
5
11

=1×

5
11

=

5
11

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