1.9+0.99+0.999+.+0.999999999+0.9999999999=多少?_数学解答

1.9+0.99+0.999+.+0.999999999+0.9999999999=多少?

人气：358 ℃　时间：2020-04-27 09:08:26

解答

=2-0.1
+ 1-0.01
+ 1-0.001
+...
+1-0.000000001
+1-0.0000000001
= 11-0.1111111111
=10.8888888889