Question 467865
If 8i is a zero, then so is -8i.  If 10i is a zero, then so is -10i.

==> the polynomial is f(x) = (x-8i)(x+8i)(x-10i)(x+10i) = {{{(x^2 + 64)(x^2 + 100)}}} = {{{x^4 + 164x^2 + 6400}}}.