问题 解答题
下面各题怎样简便就怎样算.
3
8
×
2
5
×8
(
5
12
+
7
8
)
×24
1
8
×15+
1
8
×9+1
(
1
2
+
1
7
)
×2×7
8
25
×
17
8
-
8
25
×
7
8

3
4
×(
3
2
-
1
6
)
答案

(1)

3
8
×
2
5
×8,

=

3
8
×8×
2
5

=3×

2
5

=1.2;

(2)(

5
12
+
7
8
)×24,

=

5
12
×24+
7
8
×
24,

=10+21,

=31;

(3)

1
8
×15+
1
8
×9+1,

=

1
8
×(15+1)+1,

=

1
8
×16+1,

=2+1,

=3;

(4)(

1
2
+
1
7
)×2×7,

=

1
2
×2×7+
1
7
×2×7

=7+2,

=9;

(5)

8
25
×
17
8
-
8
25
×
7
8

=

8
25
×(
17
8
-
7
8
),

=

8
25
×
10
8

=

2
5

(6)

3
4
×(
3
2
-
1
6
),

=

3
4
×
8
6

=1.

单项选择题
单项选择题