Since, RHS is an even integer. Then LHS is an even integer. So, either both x and y are even integers or both of there are odd integers. Now, x4−y4 = (x−y)(x+y)(x2+y2) ⇒x−y,x+y,x2+y2 must be an even integer. Therefore, (x−y)(x+y)(x2+y2) must be divisible by 8 and but RHS is not divisible by 8. Hence, the given equation has no solution.