Question

What are the possible numbers of positive real, negative real, and complex zeros of
f(x) = -7x4 - 12x3 + 9x2 - 17x + 3?

Answer 1

use descartes rule of sign

Answer 2

let x=1, and count how many times the operations change; that is the number of possible positive zeros

let x=-1, and count how many times the operations change; that is the number of possible negative zeros

complex zeroes come in pairs and will eat up your real zeros if need be