Thread: Probability

Let X and Y be independant poisson processes. If X+Y=n, find E[(X-Y)^2/X+Y]

i have subsituted in X-Y=n-2Y and X+Y=n this gives me the following:

E[n^2/n]-4E[nY/n]+4E[Y^2/n] which i am not sure how to simplify

we need to know the parameter involved with these Poissons
and you need to do more than plug in n, for X+Y.

the parameters are a for X and b for Y, they have no specified values.
How can i go about solving this?