Hello from MrBillDoesMath!
Answer:
x^7 - 18 x^6 + 125 x^5 - 522 x^4 + 1852 x^3 - 3960 x^2 + 1728 x - 3456
See Discussion for details.
Discussion:
The polynomial is
(x-6)^3 * (x-4i)(x+4i)(x-i)(x+i) =
x^7 - 18 x^6 + 125 x^5 - 522 x^4 + 1852 x^3 - 3960 x^2 + 1728 x - 3456
Thank you,
MrB
