Answer:
x = - 7, x = 6
Step-by-step explanation:
to find the x- intercepts set f(x) = 0, that is
x² + x - 42 = 0
To factor, consider the factors of - 42 which sum to + 1
These are + 7 and - 6
(x + 7)(x - 6) = 0
equate each factor to zero and solve for x
x + 7 = 0 ⇒ x = - 7
x - 6 = 0 ⇒ x = 6
