Since -5i is a zero, then its complex conjugate +5i is also a zero of the function.
Therefore,
x + 5i, x - 5i , and x - 3 are factors of the polynomial.
Hence, the polynomial function, P(x), of the lowest degree with rational coefficients is given by

Which implies that

Hence the polynomial is
Use MathPapa.com. Icame out withe the awnser 1