Find all the zeros of the function below

Question

Find all the zeros of the function below y=x^4+x^3-24x^2-25x-25

Answer 1

The only possible rational roots are +5 and -5, which are, in fact roots.

Division of the expression by x² - 25 gives the trinomial x² + x + 1

and the quadratic formula gives (1/2)(-1 + isqrt(3)) and its conjugate