问题 解答题
用递等式计算,能简算的要简算:
5
18
+
13
18
×9

11
27
+(
5
8
+
2
27
)×8
(5.6-1.6÷2)×2.5
5
6
+
7
12
+
3
8
)÷
1
48
1064-780÷0.75+8.25
8
9
-(
1
6
+0.25)
÷2.25.
答案

(1)9×

5
18
+
13
18
×9,

=9×(

5
18
+
13
18
),

=9×1,

=9;

(2)

11
27
+(
5
8
+
2
27
)×8,

=

11
27
+
5
8
×8+
2
27
×8,

=(

11
27
+
16
27
)+5,

=1+5,

=6;

(3)(5.6-1.6÷2)×2.5,

=(5.6-0.8)×2.5,

=4.8×2.5,

=12;

(4)(

5
6
+
7
12
+
3
8
)÷
1
48

=

5
6
×48+
7
12
×48+
3
8
×48,

=40+28+18,

=86;

(5)1064-780÷0.75+8.25,

=1064-1040+8.25,

=24+8.25,

=32.25;

(6)

8
9
-(
1
6
+0.25)÷2.25,

=

8
9
-
5
12
÷2.25,

=

8
9
-
5
27

=

19
27

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