能简算的用简便方法计算. (54+9/13)÷9 13÷(1/4+5/6)×3/4 (5/6-3/4)÷3/10 3.1×99+3.1 5/7×16.31-2.31÷7/5 36÷[(5/6-1/3)×3].

问题描述:

能简算的用简便方法计算.
(54+

9
13
)÷9          
13÷(
1
4
+
5
6
3
4

5
6
-
3
4
)÷
3
10

3.1×99+3.1          
5
7
×16.31-2.31÷
7
5

36÷[(
5
6
-
1
3
)×3].

(1)(54+

9
13
)÷9,
=(54+
9
13
)×
1
9

=54×
1
9
+
9
13
×
1
9

=6+
1
13

=6
1
13

(2)13÷(
1
4
+
5
6
)×
3
4

=13×
12
13
×
3
4

=9;
(3)(
5
6
-
3
4
)÷
3
10

=
1
12
÷
3
10

=
5
18

(4)3.1×99+3.1,
=3.1×(99+1),
=3.1×100,
=310;   
(5)
5
7
×16.31-2.31÷
7
5

=
5
7
×16.31-2.31×
5
7

=
5
7
×(16.31-2.31),
=
5
7
×14

=10;
(6)36÷[(
5
6
-
1
3
)×3],
=36÷[
1
2
×3
],
=36÷
3
2

=24.