问题 解答题
8
9
+
8
153
+
8
425
+
8
825
+
8
1353
+
8
2009
=______.
答案

8
9
+
8
153
+
8
425
+
8
825
+
8
1353
+
8
2009

=1-

1
9
+
8
9×17
+
8
17×25
+
8
25×33
+
8
33×41
+
8
41×49

=1-

1
9
+
1
9
-
1
17
+
1
17
-
1
25
+
1
25
-
1
33
+
1
33
-
1
41
+
1
41
-
1
49

=1-

1
41

=

48
49

故答案为:

48
49

单项选择题