Answer:
15
Step-by-step explanation:
Given that the x- intercepts are x = - 3 and x = - 5
Then the factors are (x + 3) and (x + 5)
f(x) is then the product of the factors, that is
f(x) = (x + 3)(x + 5) ← expand factors using FOIL
f(x) = x² + 8x + 15 ← constant term is 15