join multiple queries error

First query

SELECT a.*,
       ifnull(cnt_all,0) total_drivers,
       ifnull(cnt_active,0) active_drivers,
       ifnull(cnt_idle,0) idle_drivers
FROM ta_agent a
LEFT JOIN
  (SELECT agent_id,
          count(*) cnt_all
   FROM ta_drivers
   GROUP BY agent_id) cnt ON a.agent_id=cnt.agent_id
LEFT JOIN
  (SELECT agent_id,
          count(*) cnt_idle
   FROM ta_drivers
   WHERE last_viewed=0
   GROUP BY agent_id) idle ON a.agent_id=idle.agent_id
LEFT JOIN
  (SELECT agent_id,
          count(*) cnt_active
   FROM ta_drivers
   WHERE last_viewed=1
   GROUP BY agent_id) active ON a.agent_id=active.agent_id

Second query

SELECT FROM_UNIXTIME(date_of_registration, '%Y-%m-%d %H:%i:%s') AS user_registeredon
FROM ta_agent a,
     ta_subscription s
WHERE s.agent_id = a.agent_id

These two queries working fine when I run separately. I want to join these two queries. I have tried to join these two queries but I got this error Every derived table must have its own alias

I have tried this

select a.*, ifnull(cnt_all,0) total_drivers,ifnull(cnt_active,0) active_drivers, ifnull(cnt_idle,0) idle_drivers
    from ta_agent a left join (select agent_id, count(*) cnt_all
                       from ta_drivers
                       group by agent_id) cnt on a.agent_id=cnt.agent_id

    left join (select agent_id, count(*) cnt_idle
                       from ta_drivers
                       where last_viewed=0
                       group by agent_id) idle on a.agent_id=idle.agent_id

    left join (select agent_id, count(*) cnt_active
                       from ta_drivers
                       where last_viewed=1
                       group by agent_id) active on a.agent_id=active.agent_id

    left join(SELECT FROM_UNIXTIME( date_of_registration, '%Y-%m-%d %H:%i:%s' ) AS user_registeredon FROM ta_subscription WHERE agent_id = a.agent_id)

I don't think this is the correct method to get the result..