What are the zeros of the function?
f(x) = x2 - 4x – 5

Its the second one. x=-1 and x=5
If you factor x^2-4x-5 you get (x+1)(x-5) because you’re looking for something that multiplies to give you 5 (c) and something that adds to give you -4 (b). in this case that would be 1 and -5. then you set both (x+1) and (x-5) equal to zero and solve. this gives you your x intercepts/zeros. -1 and 5