问题 解答题
下面各题,能简算的要简算.
(1)30.1-16.8÷3.5×6.2
(2)27×99
(3)
5
4
×2.5×
4
5
×0.4
(4)
7
23
÷8+
7
23
×
7
8

(5)15×
1
7
×(
2
3
×
7
10

(6)
8
9
÷[(
4
6
-
1
3
)÷
1
2
].
答案

(1)30.1-16.8÷3.5×6.2,

=30.1-4.8×6.2,

=30.1-29.76,

=0.34;

(2)27×99,

=27×(100-1),

=27×100-27×1,

=2700-27,

=2673;

(3)

5
4
×2.5×
4
5
×0.4,

=(

5
4
×
4
5
)×(0.4×2.5),

=1×1,

=1;

(4)

7
23
÷8+
7
23
×
7
8

=

7
23
×
1
8
+
7
23
×
7
8

=

7
23
×(
1
8
+
7
8
),

=

7
23
×1,

=

7
23

(5)15×

1
7
×(
2
3
×
7
10
),

=(15×

2
3
)×(
1
7
×
7
10
),

=10×

1
10

=1;

(6)

8
9
÷[(
4
6
-
1
3
)÷
1
2
],

=

8
9
÷[
1
3
÷
1
2
],

=

8
9
÷
2
3

=

4
3

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