what are the possible combinations of real and imaginary zeros for the polynomial below?

what are the possible combinations of real and imaginary zeros for the polynomial below?

      P(x) = 3x5-2x4+x2-20.5x-5

Radioactive gold-198 , used in imaging the structure of the liver, has a half-life of 2.67 days. If we start with 50 milligramms of the isotope, how many milligrams will be left after:

a) 1/2 day

b) 1 week