问题 解答题
怎样算简便就怎样算.
3
4
+
5
8
×
2
5
5
3
-
2
7
-
5
7
7
9
÷
11
5
+
2
9
×
5
11
8
9
+(1-
3
4
)×
4
9
 
4.85-
5
9
+5.15-
4
9
     
1
13
+
12
13
×(
5
2
-
1
3
答案

(1)

3
4
+
5
8
×
2
5

=

3
4
+
1
4

=1;

(2)

5
3
-
2
7
-
5
7

=

5
3
-(
2
7
+
5
7
),

=

5
3
-1,

=

2
3

(3)

7
9
÷
11
5
+
2
9
×
5
11

=

7
9
×
5
11
+
2
9
×
5
11

=(

7
9
+
2
9
)×
5
11

=1×

5
11

=

5
11

(4)

8
9
+(1-
3
4
)×
4
9

=

8
9
+
1
4
×
4
9

=

8
9
+
1
9

=1;

(5)4.85-

5
9
+5.15-
4
9

=4.85+5.15-

5
9
-
4
9

=(4.85+5.15)-(

5
9
+
4
9
),

=10-1,

=9;

(6)

1
13
+
12
13
×(
5
2
-
1
3
),

=

1
13
+
12
13
×
13
6

=

1
13
+2,

=2

1
13

问答题
单项选择题