Answer:
f(x) = x^3 -5x^2 +25x -125
Step-by-step explanation:
For zero x=a, one of the factors is (x -a). If the polynomial has integer coefficients, its complex roots come in conjugate pairs. So, the roots are ...
roots: -5i, 5i, 5
factors: (x -(-5i))(x -5i)(x -5)
Multiplying these out gives your polynomial as ...
f(x) = (x^2 +25)(x -5)
f(x) = x^3 -5x^2 +25x -125