问题 解答题
3
4
×2=
3
4
+
1
2
=
2
5
×15=
7
8
×
4
21
=
1
2
+
1
7
-
1
2
+
1
7
=
2
3
-
1
2
=
2
3
=
12
17
=
(12+
1
5
)×
1
6
=
1
2
×
1
7
÷
1
2
×
1
7
=
答案

3
4
×2=1
1
2
3
4
+
1
2
=1
1
4
2
5
×15=6
7
8
×
4
21
=
1
6

1
2
+
1
7
-
1
2
+
1
7
=
2
7
2
3
-
1
2
=
1
6
2
3
=12 0×
12
17
=0

(12+

1
5
)×
1
6
=
1
30
1
2
×
1
7
÷
1
2
×
1
7
=
1
49

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