Hello,
  I was looking at the original question  that was posted and answered by 
  your team:
  http://mathcentral.uregina.ca/QQ/database/QQ.09.07/s/donna1.html
I used the 7 and 4 as example and not looking for 39 per original 
  question:
A=7
  B=4
7+ 4 =11  and   7-4 = 3
We end up with   11 +3  = 14
A= 14/2   give use 7
B =  how do you solve for B or 4 with out knowing anything about 3 or any other numbers ?
Thank you
  Ali