问题 解答题
用简便方法计算.
12-
7
12
-
5
12
                                
7
13
×
6
7
+
6
7
÷
13
6
答案

(1)12-

7
12
-
5
12

=12-(

7
12
+
5
12
),

=12-1,

=11;

(2)

7
13
×
6
7
+
6
7
÷
13
6

=

7
13
×
6
7
+
6
7
×
6
13

=(

7
13
+
6
13
)×
6
7

=1×

6
7

=

6
7

判断题
单项选择题