A rope of mass M and length L lies on a frictionless table, with a short portion

hanging through a hole. Initially the rope is at rest. Evaluate A and B so that the initial conditions are satisfied.

Ok, so I understand the problem and have gotten the final 2 equations (according to my book):

yAe^(yt)-yBe^(-yt)=0

Lo=Ae^(yt)+Be^(-yt)

It looks like, according to the first equation, Be^(-yt)=Ae^(yt). Plugging this into the second equation, Lo=2Ae^(yt) and Lo=2Be^(-yt). Is this all that is meant by "evaluate A and B"? If not, where do I go from here?