x and y;



Description turned into equations:  


x+y=2(y-x),     (1) 
3(y-x)=2y       (2)


From equation (1)

3x = y          (3)


From equation (2)

y = 3x          (4)


Equations (3) and (4) are identical. 

It means that lesser number, x, may have any value, and greater number, y, must be 3 times the smaller.


ANSWER.  Lesser number, x, may have any positive real value, and greater number, y, must be 3 times the smaller.