Answer:
(3n - 8)(2n + 5)
Explanation:
6n² - n - 40
Consider the factors of the product of the coefficient of the n² term and the constant term which sum to give the coefficient of the n- term
product = 6 × - 40 = - 240 and sum = - 1
The factors are - 16 and + 15
Use these factors to split the n- term
6n² - 16n + 15n - 40 ( factor the first/second and third/fourth terms )
2n(3n - 8) + 5(3n - 8) ← factor out (3n - 8) from each term
(3n - 8)(2n + 5)
Then
6n² - n - 40 = (3n - 8)(2n + 5)