You can put this solution on YOUR website!
I assume you know synthetic division.
Since the coefficients of the polynomial add up to zero
"1" is a zero of the polynomial.
Using "1" in synthetic division you find a quotient
of 1 9 25 17
Using "-1" in synthetic division you next get a quotient
of 1 8 17 or x^2 +8x + 17
This you can solve with the quadratic formula and find
zeroes at x= -4+i and -4-i
So you have zeroes at 1, -1, -4+i, and -4-i