In addition to what has already been stated, this is a number properties question, without testing any numbers (not sure if that's faster or slower) but:
x>y>2 and noting that they are prime means that X and y are odd.
also
X^2 - y^2= (x+y)(x-y) so now you have (odd+odd)(odd-odd) which = even * even, which means that at minimum the numbers have 2 powers of 2 in them so it must be divisible by 4.
Just how I thought of it....
x>y>2 and noting that they are prime means that X and y are odd.
also
X^2 - y^2= (x+y)(x-y) so now you have (odd+odd)(odd-odd) which = even * even, which means that at minimum the numbers have 2 powers of 2 in them so it must be divisible by 4.
Just how I thought of it....