Answer:
(a) (x -(7 +i))
Step-by-step explanation:
You want to know what must be a factor of f(x) if it has roots -9 and 7-i.
Complex roots
The complex roots of a polynomial with real coefficients are always found in conjugate pairs. Since 7-i is a root, its conjugate, 7+i, must also be a root. The corresponding factor is ...
(x -(7 +i))
If 7-i is a root of f(x), then (x -(7+i)) must be a factor.
