how to substract columns from two different tables in Power BI

[Saswa_D]

Hi Team,

Need your help please.
I have two tables - Master Table and Target table:
Master Table:

Target table:

Now in Target table I want to calculate Target Column as:
Target Coumn= Efficiency benefit - 'Master Table'[Cost Avoidance]- 'Master Table'[Loss].
And the I can present the Target table in a matrix.
I have tried creating DAX using SUM and Related functions but it doesn't help.
SUM summarizes and returns one value whereas Related did not work at all.

Please anyone can help me here ? 

[AntrikshSharma · Accepted solution]

@Saswa_D use this:

SUMX ( 
    RELATEDTABLE ( 'Master Table' ), 
    Master Table'[Cost Avoidance]- 'Master Table'[Loss] 
)