Answer:
3x(x - 4)(x + 2)
Explanation:
Given
3x³ - 6x² - 24x ← factor out common factor of 3x from each term
= 3x(x² - 2x - 8) ← factor the quadratic
Consider the factors of the constant term (- 8) which sum to give the coefficient of the x- term.
The factors are - 4 and + 2, since
- 4 × 2 = - 8 and - 4 + 2 = - 2, thus
x² - 2x - 8 = (x - 4)(x + 2) and
3x³ - 6x² - 24x = 3x(x - 4)(x + 2)