问题 解答题
1-
1
10
-
1
100
-
1
1000
答案

1-

1
10
-
1
100
-
1
1000

=1-(

1
10
+
1
100
+
1
1000
),

=1-(

100
1000
+
10
1000
+
1
1000
),

=1-

111
1000

=

889
1000

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