Only the first one, 'That is worth reading' is correct. 'Worth' is an adjective, and it is followed by the gerund (ing form).
Don't believe anyone who tells you that you can say 'worth to' with the infinitive - this is wrong.
27 de junio de 2016
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That is worth reading
27 de junio de 2016
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That is worth reading
27 de junio de 2016
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You should use "reading"
28 de junio de 2016
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It/ That is worthy to read.
27 de junio de 2016
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