Answer:
x = - 1, x = 8
Step-by-step explanation:
Given
8 + 7x - x² = 0 ( multiply through by - 1 and arrange into standard form )
x² - 7x - 8 = 0 ← in standard form
(x - 8)(x + 1) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 1 = 0 ⇒ x = - 1
x - 8 = 0 ⇒ x = 8