问题 解答题
计算下面各题,怎样简便就怎样计算.
2-
3
2
×
10
21
-
2
7
2
9
×4+
2
9
×5
1
3
+
1
4
-
1
6
)×24
8
17
÷7+
1
7
×
9
17
7
8
÷(
1
4
+
1
3
[1-(
1
4
+
3
8
)]÷
1
2
3
4
×
2
3
+
1
3
÷
5
6
4
5
×
3
4
÷
3
8
5
8
+
3
4
÷
15
16
+
3
8
答案

(1)2-

3
2
×
10
21
-
2
7

=2-

5
7
-
2
7

=2-(

5
7
+
2
7
),

=2-1,

=1;

(2)

2
9
×4+
2
9
×5,

=

2
9
×(4+5),

=

2
9
×9,

=2;

(3)(

1
3
+
1
4
-
1
6
)×24,

=

1
3
×24+
1
4
×24-
1
6
×24,

=8+6-4,

=14-4,

=10;

(4)

8
17
÷7+
1
7
×
9
17

=

8
17
×
1
7
+
1
7
×
9
17

=(

8
17
+
9
17
)×
1
7

=1×

1
7

=

1
7

(5)

7
8
÷(
1
4
+
1
3
),

=

7
8
÷
7
12

=

3
2

(6)[1-(

1
4
+
3
8
)]÷
1
2

=[1-

5
8
1
2

=

3
8
÷
1
2

=

3
4

(7)

3
4
×
2
3
+
1
3
÷
5
6

=

1
2
+
2
5

=

9
10

(8)

4
5
×
3
4
÷
3
8

=

4
5
×
3
4
×
8
3

=

8
5

(9)

5
8
+
3
4
÷
15
16
+
3
8

=

5
8
+
4
5
+
3
8

=(

5
8
+
3
8
)+
4
5

=1+

4
5

=1

4
5

综合
单项选择题