Answer:
3(x - 12)(x + 2)
Explanation:
Given
3x² - 30x - 72 ← factor out 3 from each term
= 3(x² - 10x - 24) ← factor the quadratic
Consider the factors of the constant term (- 24) which sum to give the coefficient of the x- term (- 10)
The factors are - 12 and + 2 , since
- 12 × 2 = - 24 and - 12 + 2 = - 10 , thus
x² - 10x - 24 = (x - 12)(x + 2) and
3x² - 30x - 72 = 3(x - 12)(x + 2)