问题 解答题
脱式计算(能简算的要简算)
2
3
+
2
5
+
3
5
1
4
+
1
6
+
5
12
5
7
-
1
2
+
1
7
1-
2
11
-
9
11
答案

(1)

2
3
+
2
5
+
3
5

=

2
3
+(
2
5
+
3
5
),

=

2
3
+1,

=1

2
3

(2)

1
4
+
1
6
+
5
12

=

5
12
+
5
12

=

5
6

(3)

5
7
-
1
2
+
1
7

=

5
7
+
1
7
-
1
2

=

6
7
-
1
2

=

5
14

(4)1-

2
11
-
9
11

=1-(

2
11
+
9
11
),

=1-1,

=0.

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