问题 解答题
用递等式计算,能简算的要简算.
4
5
+
11
15
+
3
10
60.62-(9.2+12.62)
6.8+
1
6
+3.2+
5
6
15
11
-
3
7
-
4
7
9
11
+
5
6
+
2
11
-
1
6
7
8
-(
7
10
-
1
8
答案

(1)

4
5
+
11
15
+
3
10

=

23
15
+
3
10

=1

5
6

(2)60.62-(9.2+12.62),

=60.62-9.2-12.62,

=48-9.2,

=38.8;

(3)6.8+

1
6
+3.2+
5
6

=(6.8+3.2)+(

1
6
+
5
6
),

=10+1,

=11;

(4)

15
11
-
3
7
-
4
7

=

15
11
-(
3
7
+
4
7
),

=

15
11
-1,

=

4
11

(5)

9
11
+
5
6
+
2
11
-
1
6

=(

9
11
+
2
11
)+(
5
6
-
1
6
),

=1+

2
3

=1

2
3

(6)

7
8
-(
7
10
-
1
8
),

=

7
8
+
1
8
-
7
10

=1-

7
10

=

3
10

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