delE = 1/2 k (dX^2 - dx^2); where dX = .6 m and dx = .3 m.
So we need k, the constant, to get the "difference."
But I'm guessing you really want E/e = 1/2 kdX^2/1/2 kdx^2 = (dX/dx)^2 = 4 so E = 4e, which is to say spring A has 4 times more energy than B. ANS.