Hi, Even I think for the first part we can do the general maximization. and for the second part we can assume the utility function as any of the following
U(x,y)=x+y or U(x,y)=min(x,y) or U(x,y)=(xy)^1/2 and then proceed with the general maximization problem since the functions are symmetric we will get x=y
I may be wrong but this is what i thought on this question.