问题 解答题
能简便计算的用简便方法计算.
10
13
÷
35
26
×
7
3
4
7
×
1
4
+0.25×
3
7
-
1
4
7
8
+
13
16
)÷
13
16
1
7
×
5
12
+
5
12
÷
7
5
1
5
÷[(
2
3
+
1
5
)×
1
13
]
1
2
+
1
6
+
1
12
+
1
20
+…
1
90
答案

(1)

10
13
÷
35
26
×
7
3

=

4
7
×
7
3

=1

1
3

(2)

4
7
×
1
4
+0.25×
3
7
-
1
4

=0.25×(

4
7
+
3
7
-1),

=0.25×0,

=0;

(3)(

7
8
+
13
16
)÷
13
16

=

7
8
×
16
13
+
13
16
×
16
13

=1

1
13
+1,

=2

1
13

(4)

1
7
×
5
12
+
5
12
÷
7
5

=

5
12
×(
1
7
+
5
7
),

=

5
12
×
6
7

=

5
14

(5)

1
5
÷[(
2
3
+
1
5
)×
1
13
],

=

1
5
÷[
13
15
×
1
13
],

=

1
5
÷
1
15

=3;

(6)

1
2
+
1
6
+
1
12
+
1
20
+…
1
90

=1-

1
2
+
1
2
-
1
3
+
1
3
-
1
4
+
1
4
-
1
5
…+
1
9
-
1
10

=1-

1
10

=

9
10

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