问题 解答题
(1)762-357+438-243
(2)(
3
4
+
1
6
-
5
12
÷
1
36

(3)(200.6×365+2006×63.5)×40%
(4)4
1
5
×5+32
4
7
÷4+0.25×124

(5)(0.5+
1
4
+3
1
8
÷1.25)÷(5
1
4
-1.25×1
3
5

(6)
2
3
+
2
15
+
2
35
+…+
2
399
答案

(1)762-357+438-243,

=(762+438)-(357+243),

=1200-600,

=600;

(2)(

3
4
+
1
6
-
5
12
÷
1
36

=(

3
4
+
1
6
-
5
12
)×36,

=

3
4
×36+
1
6
×36-
5
12
×36,

=27+6-15,

=33-15,

=18;

(3)(200.6×365+2006×63.5)×40%,

=(200.6×365+200.6×635)×40%,

=(365+635)×200.6×40%,

=1000×200.6×0.4,

=200600×0.4,

=80240;

(4)4

1
5
×5+32
4
7
÷4+0.25×124,

=(4+

1
5
)×5+(32+
4
7
)×
1
4
+0.25×4×31,

=4×5+

1
5
×5+32×
1
4
+
4
7
×
1
4
+1×31,

=20+1+8+

1
7
+31,

=(20+1+8+31)+

1
7

=60+

1
7

=60

1
7

(5)(0.5+

1
4
+3
1
8
÷1.25)÷(5
1
4
-1.25×1
3
5
),

=(0.5+

1
4
+2.5)÷(5
1
4
-2),

=(0.5+2.5+

1
4
)÷(5
1
4
-2),

=(3+

1
4
)÷3
1
4

=3

1
4
÷3
1
4

=1;

(6)

2
3
+
2
15
+
2
35
+…+
2
399

=(1-

1
3
)+(
1
3
-
1
5
)+(
1
5
-
1
7
)+…+(
1
19
-
1
21
),

=1-

1
3
+
1
3
-
1
5
+
1
5
-
1
7
+…-
1
19
+
1
19
-
1
21

=1-

1
21

=

20
21

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