Answer:
3(x - 3)(x + 2)
Step-by-step explanation:
take out a common factor of 3 from each term
= 3(x² - x - 6)
to factor the quadratic consider the factors of - 6 which sum to - 1
These are - 3 and + 2, hence
3x² - 3x - 18 = 3(x - 3)(x + 2) ← in factored form