how to subtract a specific row from another row in a sql statement ?

  Hello Experts,

i have 2 queries combined with union all 

and there is a outer main select statement that add and subtract from a 2 inner queries - find attached query statement in "my sql query" file -

I have attached the output of the query in an Excel file within 2 tabs.

 1st tab: named " query union all " that displays the output without the outer select statement

  2nd tab: named "query combined" that displays the output with the outer select statement

 

if we look at the second tab in the excel file my target is to diplay data as showed

    

    as subract   200.87 from 40159.23 and put the result in amount_cr_usd column