问题 解答题
用递等式计算.
①[1-(
1
8
+
2
3
)]×36
②(
2
9
+
7
12
)×36
③7.5×4.7+4.7×2.5
④25.3×12-33.46÷0.35
5
6
×[
2
3
÷(1-
13
15
)]
1
4
+(
5
8
-
3
10
)÷
1
2
答案

①[1-(

1
8
+
2
3
)]×36,

=[1-(

3
24
+
16
24
)]×36,

=[1-

19
24
]×36,

=

5
24
×36,

=

15
2

②(

2
9
+
7
12
)×36,

=36×

2
9
+
7
12
×36

=8+21,

=29;

③7.5×4.7+4.7×2.5,

=4.7×(7.5+2.5),

=4.7×10,

=47;

④25.3×12-33.46÷0.35,

=303.6-95.6,

=208;

5
6
×[
2
3
÷(1-
13
15
)],

=

5
6
×[
2
3
÷
2
15
],

=

5
6
×[
2
3
×
15
2
],

=

5
6
×5,

=4

1
6

1
4
+(
5
8
-
3
10
)÷
1
2

=

1
4
+(
25
40
-
12
40
)×2,

=

1
4
+
13
40
×2,

=

5
20
+
13
20

=

9
10

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