What equations can you use to get the number 12

If 2(a^2+b^2)=(a+b)^2 then, > a+b=0, > ab=0, > a=b, > 2a=b

Due to financial difficulties the owner of 4 skateboard stores is going to close 2 of his stores. based on the money earned at each store, which two stores should remain open?

Can someone me with this graph problem by the way i need to know the answers by today since this assignment is due ! !