问题 解答题
能简算的要简算.
5
9
×7+
5
9
×11
4
25
×99+
4
25
[1-(
1
4
+
3
8
)]÷
1
4
答案

(1)

5
9
×7+
5
9
×11,

=

5
9
×(7+11),

=

5
9
×18,

=10;

(2)

4
25
×99+
4
25

=

4
25
×(99+1),

=

4
25
×100,

=16;

(3)[1-(

1
4
+
3
8
)]÷
1
4

=[1-

5
8
]÷
1
4

=

3
8
×4,

=1.5.

单项选择题
单项选择题