问题 填空题
1-
1
2
{1-
1
3
[1-
1
4
(1-
1
5
)]}
=______.
答案

1-

1
2
{1-
1
3
[1-
1
4
(1-
1
5
)]},

=1-

1
2
{1-
1
3
[1-
1
4
+
1
20
]},

=1-

1
2
{1-
1
3
×
4
5
},

=1-

1
2
{1-
4
15
},

=1-

1
2
×
11
15

=1-

11
30

=

19
30

故答案为

19
30

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