Answer:
(x + 7)(x² - 8)
Explanation:
x³ + 7x² - 8x - 56 =
let's put the total multiplier x² out of brackets
x²(x + 7) - 8x - 56 =
let's put the total multiplier -8 out of brackets
x²(x + 7) - 8(x + 7) =
let's put the total multiplier (x + 7) out of brackets
(x + 7)(x² - 8)