Answer:
The spring was compressed the following amount:

Explanation:
Use conservation of energy between initial and final state, considering that the surface id frictionless, and there is no loss in thermal energy due to friction. the total initial energy is the potential energy of the compressed spring (by an amount
), and the total final energy is the addition of the kinetic energies of both masses:



The sphere slow down due to friction force between the surface of the sphere and the surface on that the sphere is rolling . The friction force acting against the motion of the sphere. Thats why it is slowed down. In fact not only a sphere, anything can not slow down untill a force act against it's motion.
One point will be X1,Y1 and the other will be X2,Y2. It does not matter which is which except that X1 and Y1 have to be the same point and X2 and Y2 have to be the same point. For example, let's say you were given (2,3) and (6,8). No matter which point is X1,Y1 and the other is X2,Y2, the slope will still be 5/4.
The rise is the change in y from one point to the other. The run would be the change in x from one point to the other.