Summing Line Items In SQL
Instead of posting again, you could have updated your previous question.

The issue with the old query is that it wasn't calculating tax *.75 appropriately.

rextester: http://rextester.com/ZGQ51639

Declare @Calc Table
(
  employee varchar(100)
  ,annualsales decimal(10,2)
  ,dep1sales decimal(10,2)
  ,dep2sales decimal(10,2)
  ,dep3sales decimal(10,2)
  ,dep4sales decimal(10,2)
  ,dep5sales decimal(10,2)
  ,tax decimal(10,2)
)


Insert Into @Calc (employee, annualsales, dep1sales, dep2sales, dep3sales, dep4sales, dep5sales, tax) Values
('emp1', '1111.00', '26.12', '83.00', '16.55', '21.77', '87.08', null)
,('emp1', null, '28.07', '11.00', '101.24', '47.03', '76.19', null)
,('emp1', null, '35.25', '7.00', '33.64', '43.54', '43.52', null)
,('emp2', 1954.85, '1120.65', '0', '0', '0', '0', 392.70)


Select 
employee
,AnnualSales=sum(isnull(annualsales,0)) 
,DeptSales  =sum(isnull(dep1sales,0)+isnull(dep2sales,0)+isnull(dep3sales,0)+isnull(dep4sales,0)+isnull(dep5sales,0)) 
,Tax        =sum(isnull(tax,0)) 
,[SomeCalc] =(sum(isnull(annualsales,0))
             -(
               sum(isnull(dep1sales,0)+isnull(dep2sales,0)+isnull(dep3sales,0)+isnull(dep4sales,0)+isnull(dep5sales,0)) 
             +(sum(isnull(tax,0))*.75)
              )
             )
            /nullif(sum(isnull(annualsales,0)),0)
from @Calc
group by employee
order by employee asc