The number of integral solutions of x2−y2=352706 is
276
0
720
infinite
As 352706 is even, either both x and y are even or both x and y are odd.
If x ,y are both even, x2−y2 is divisble by 4, but 352706 is not divisible by 4.
If x ,y are both odd, x2−y2 is divisble by 4, but 352706 is not divisible by 4.