Question

What are the possible number of positive, negative, and complex zeros of f(x) = 3x4 - 5x3 - x2 - 8x + 4 ?
the answer is: Positive: 2 or 0; Negative: 4, 2, or 0; Complex: 6, 4, 2, or 0

can you please explain why thats the answer.

Answer 1

I can't explain all those answers unless you are suppose to select the correct number from all those choices.
There are two (2) positive real roots and two complex roots with negative real components and one with a positive imaginary, the other with a negative imaginary component.

Answer 2

Total roots are 4, 2 real and 2 complex