To help us help you, rather than posting a picture of the data, please see the first link under "Helpful Links" in my signature line below and post your data as per that article. Otherwise the answer is simply, express a ROW_NUMBER() over the partitions formed by the articulo column in descending order by fecha_hora_transac in a CTE and select only the rows with a ROW_NUMBER() of "1" from that.
--Jeff Moden
Change is inevitable... Change for the better is not.