I am lost on this

Question

Find all real zeros of the polynomial f(x)=x3+5x2−16x−80

 and determine the multiplicity of each.

Select one:

a. x = -5, multiplicity 3

b. x = -5, multiplicity 2; x = -4, multiplicity 1

c. x = 64, multiplicity 2; x = 36, multiplicity 2

d. x = 4, multiplicity 1; x = -4, multiplicity 1; x = -5, multiplicity 1

Answer 1

You could just factor the polynomial.

Or, since its multiple choice, you could just test the different answers to see which one works.