If the roots are -sqrt(5), sqrt(5), and -3, then the three factors of the polynomial are: (x + sqrt(5)), (x - sqrt(5)), and (x+3)
Let's multiply the first two factors together.
(x + sqrt(5)) * (x - sqrt(5)) = x^2 - 5
Let's multiply this by the third factor (x+3).
(x^2 - 5) * (x+3) = x^3 + 3x^2 -5x - 15
The correct answer is the last polynomial in the list of choices above.
