问题 解答题
(1)36×(
5
9
+
3
4
-
11
8

(2)[
1
2
-(
3
8
×
11
12
+
3
8
×
1
12
)]÷
3
4

(3)51×
40
50
(用简便方法计算)
(4){1-[
1
5
+
7
10
÷(
1
2
+
3
8
)]}×
1
2

(5)30
1
28
×
28
29
(看能否用简便方法计算
).
答案

(1)36×(

5
9
+
3
4
-
11
8
),

=36×

5
9
+36×
3
4
-36×
11
8

=20+27-49.5,

=-2.5;

(2)[

1
2
-(
3
8
×
11
12
+
3
8
×
1
12
)]÷
3
4

=[

1
2
-
3
8
×
11
12
+
1
12
)],

=[

1
2
-
3
8
],

=

1
8

(3)51×

40
50

=50×

40
50
+1×
40
50

=40+

4
5

=40

4
5

(4){1-[

1
5
+
7
10
÷(
1
2
+
3
8
)]}×
1
2

={1-[

1
5
+
7
10
÷
7
8
]}×
1
2

={1-[

1
5
+
4
5
]}×
1
2

={1-1}×

1
2

=0×

1
2

=0;

(5)30

1
28
×
28
29

=29×

28
29
+1×
28
29
+
1
28
×
28
29

=28+(

28
29
+
1
29
),

=28+1,

=29.

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