Answer:
5 + i
Step-by-step explanation:
the Fundamental theorem of Algebra states that a polynomial of gegree n has n zeros , some of which may be complex.
A polynomial of degree 3 will therefore have 3 zeros
given x = 1 and 5 - i are two of the zeros
Complex zeros occur as conjugate pairs , then
5 - i is a zero then 5 + 1 is also a zero
the 3 zeros are x = 1 , x = 5 - i and x = 5 + i
