Answer:
(2x + 3)(x - 7)
Step-by-step explanation:
Given
2x² - 11x - 21
Consider the factors of the product of the x² term and the constant term which sum to give the coefficient of the x- term
product = 2 × - 21 = - 42 and sum = - 11
The factors are - 14 and + 3
Use these factors to split the x- term
2x² - 14x + 3x - 21 ( factor the first/second and third/fourth terms )
= 2x(x - 7) + 3(x - 7) ← factor out (x - 7) from each term
= (2x + 3)(x - 7) ← in factored form
