问题 解答题
3+
5
7
5
36
+
9
1
4
-
1
9

2008÷
2007
2009
答案

(1)3+

5
7
5
36
+
9
1
4
-
1
9

=3+

5
7
5
36
+
9
5
36

=3+

5
16
5
36

=3+

5
16×
36
5

=3+

5
576
5

=3+

25
576

=3

25
576

(2)2008÷

2007
2009

=2008×

2009
2007

=(2007+1)×

2009
2007

=2007×

2009
2007
+
2009
2007

=2009+1

2
2007

=2010

2
2007

问答题
问答题 简答题