问题 解答题
3
5
+
1
15
)×30
17×
3
16
100×
100
101
7
8
×
4
15
-
7
15
×
4
8
9
3
5
×
1
8
34-34×
26
27
答案

(1)(

3
5
+
1
15
)×30,

=

3
5
×30+
1
15
×30,

=18+2,

=20;

(2)17×

3
16

=(16+1)×

3
16

=16×

3
16
+1×
3
16

=3+

3
16

=3

3
16

(3)100×

100
101

=(101-1)×

100
101

=101×

100
101
-1×
100
101

=100-

100
101

=99

1
101

(4)

7
8
×
4
15
-
7
15
×
4
8

=

7
8
×
4
15
-
7
8
×
4
15

=

7
8
×(
4
15
-
4
15
),

=0;

(5)9

3
5
×
1
8

=(8+

8
5
)×
1
8

=8×

1
8
+
8
5
×
1
8

=1+

1
5

=1

1
5

(6)34-34×

26
27

=34×(1-

26
27
),

=34×

1
27

=

34
27

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