Answer:By the Fundamental Theorem of Algebra, a polynomial of degree n will have exactly n complex zeros. If the coefficients of that polynomial are all real (as is the case of the polynomials being discussed here), then, any non-real complex zeros of the polynomial must occur in conjugate pairs.
For example, a polynomial of degree 7 will have either 0,2,4, or 6 non-real zeros, which means it will have 7,5,3, or 1 real zeros.
