Macro to Subtract values where Ref is the same and then delete Duplicate Ref

I have data on sheet "Extracted data" where the Ref is in Col A and the Value is in Col B


I would like VBA code to do the following


1) Where The Ref in Col A is the same, then the values for the references that are the same are to be subtracted from those references that are the same and the net result to be inserted in the first ref that is the same for eg Ref 115 value 549.75 in Say A5 and Ref 115 value 549.35 in A8 . The net result is 0.40 and must go into cell A5
2) Once the above has been done, then the second duplicate reference must be deleted


I have attached sample data and manually did steps 1 and 2 above and have shown the results on sheet "Final Result"

It would be appreciated if someone could assist me