Answer:
(x - 43)(x + 3)
Step-by-step explanation:
consider the factors of the constant term (- 129) which sum to give the coefficient of the x- term (- 40)
the factors are - 43 and + 3 , since
- 43 × + 3 = - 129 and - 43 + 3 = - 40 , then
x² - 40x - 129 = (x - 43)(x + 3) ← in factored form
