问题 解答题
7
6
-
3
5
-
1
5
5
4
-(
3
7
+
1
4
)
0.5+
1
4
-0.5+
1
4
4
5
-(
7
8
-
1
5
)
17
9
-
1
6
-
5
6
+
1
9
3
7
+
1
4
-
1
14
答案

(1)

7
6
-
3
5
-
1
5

=

7
6
-(
3
5
+
1
5
),

=

7
6
-
4
5

=

11
30

(2)

5
4
-(
3
7
+
1
4
),

=

5
4
-
3
7
-
1
4

=

5
4
-
1
4
-
3
7

=1-

3
7

=

4
7

(3)0.5+

1
4
-0.5+
1
4

=(0.5-0.5)+(

1
4
+
1
4
),

=0+

1
2

=

1
2

(4)

4
5
-(
7
8
-
1
5
),

=

4
5
-
7
8
+
1
5

=

4
5
+
1
5
-
7
8

=1-

7
8

=

1
8

(5)

17
9
-
1
6
-
5
6
+
1
9

=(

17
9
+
1
9
)-(
1
6
+
5
6
),

=2-1,

=1;

(6)

3
7
+
1
4
-
1
14

=

3
7
-
1
14
+
1
4

=

5
14
+
1
4

=

17
28

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