Answer:
(x + 3)(x + 1)(x - 1)
Explanation:
Given
x³ + 3x² - x - 3
Factor the first/second and third/fourth terms
= x²(x + 3) - 1(x + 3) ← factor out (x + 3) from each term
= (x + 3)(x² - 1) ← (x² - 1) is a difference of squares, hence
= (x + 3)(x + 1)(x - 1) ← in factored form