I'm not sure what you mean by "the term that does not contain z..."
Since the coefficients are all real, complex solutions occur as conjugates, so assuming , that means and are also roots.
Therefore .
Exactly as the question says, and it a multiple choice:
If P(z) is a polynomial of degree 4 with all its coefficients real with ai, bi(a, b element R) as two of the zeros, then the term that does not contain z is:
Answers:
A) ab
B) a-b
C) a+b
D) a^3b^3
E) a^2b^2