A simple left/inner join can help
Try this-
select t1.USER_NAME as UserName, test1, test2
from
(
select b.UserName as USER_NAME, sum(a.TotalCount)*2 as test1 from [database].[dbo].table1 a ,[database].[dbo].table2 b where a.UserID = b.UserID and a.WorkAreaID = '2' group by b.UserName
) as t1
left join
(
select b.UserName as USER_NAME,sum(a.TotalCount) as test2 from [database] .[dbo].table3 a, [database].[dbo].table4 b where a.scope = 'Scrolling' and a.resources = b.UserName group by b.UserName
) as t2 on t1.USER_NAME=t2.USER_NAME
Hope, it helps :)