performance adjustment: update sys.job $ set this_date =: 1 where job =: 2 as one of the most time-consuming queries: oracle

I am currently helping some organization with the performance of its Oracle database. They use Oracle 11gR2 Standard Edition in Windows 2008. As there are no business performance packages available in this standard edition, I had to use v $ sql to query the most running ones to identify bottlenecks in performance. Using the following query:

SELECT sql_text,
time elapsed,
elapsed time / executions
FROM v $ sql - order by elapsed time / executions)) where rownum <= 10;

I returned some queries that I will analyze, but there are two rows in the results that I can not understand the reason why they should exist here:

Results for two consultations

As you can see, the query runs in sys.job $, so it must be related to the Oracle works established in this database. My questions are:

1) What do these two rows mean? I must consult dba_jobs table for more information? How should I consult them and what should I look for?

2) Both consultations seem identical, why are they repeated twice in the query result?