问题 解答题
计算下面各题.
2
9
+
4
9
+
1
9

1
2
+
2
7
+
3
14

5
6
-
1
2
+
1
4

4
7
+(
1
2
-
1
3
)
答案

(1)

2
9
+
4
9
+
1
9

=

2+4+1
9

=

7
9

(2)

1
2
+
2
7
+
3
14

=

11
14
+
3
14

=1;

(3)

5
6
-
1
2
+
1
4

=

1
3
+
1
4

=

7
12

(4)

4
7
+(
1
2
-
1
3
),

=

4
7
+
1
6

=

31
42

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