Form a third degree polynomial function with real coefficients such that -7 + i and -9 are zeros

Answer 1

the -7 + i has a conjugate partner of -7 - i
so (-7+i)(-7-i)
= 49 - i^2
= 50
-7+i + (-7-i)
= -14
so we can form the quadratic as
x^2 + 14x + 50 as one of the factors.
the other is (x+9)

so the polynomial could be
f(x) = (x+9)(x^2 + 14x + 50)