### y = -3x^{2} - 18x -20 = -(3x^{2} + 18x + 20) is not factorable. The discriminant D = 18^{2}=4(3)(20)=324-240=84. since 84 is not a perfect square, both roots are irrational.

The zeros are given by the quadratic formula: [-18√84]/6.

There are two zeros (roots, a.k.a. x-intercepts) because it's a quadratic equation when you set y=0).

*Had the discriminant been zero, there would be only one so-called double root (rational). Had D been < 0, there'd be no Real roots.*