Answer:x = - 5, x = 4Step-by-step explanation:Givenf(x) = x² + x - 20To find the zeros equate f(x) to zero, that isx² + x - 20 = 0Consider the factors of the constant term ( - 20) which sum to give the coefficient of the x- term ( + 1)The factors are + 5 and - 4, since5 × - 4 = - 20 and + 5 - 4 = + 1, hence(x + 5)x - 4) = 0 ← in factored formEquate each factor to zero and solve for xx + 5 = 0 ⇒ x = - 5x - 4 = 0 ⇒ x = 4