Answer:
x = - 12 , x = - 7
Explanation:
To solve the equation , equate to zero
x² + 19x + 84 = 0
Consider the factors of the constant term (+ 84) which sum to give the coefficient of the x- term (+ 19)
The factors are + 12 and + 7 , since
12 × 7 = 84 and 12 + 7 = 19 , then
(x + 12)(x + 7) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 12 = 0 ⇒ x = - 12
x + 7 = 0 ⇒ x = - 7