First, we look at:

...then, A will have $(x-3), and B will have $(y+3)...

...so $(y+3) will be 2 times $(x-3), or

             (y+3) = 2(x-3)

...then, B will have $(y-6), and A will have $(x+6)...

...so $(x+6) will be $(y-6)+4, or

             (x+6) = (y-6)+4

So we have this system of equations:



Simplifying:







Solve by substitution and get

, 

So A has $17 and B has $25.

Checking:

then A will have $14, and B will have $28.

And yes, indeed, $28 will be 2 times $14.

then B will have $19, and A will have $23

And, yes indeed, $23 is $4 more than $19.

Edwin