Question

a) x³ - 25x fatorado

Answer 1

$\boxed{x^3-25x=x(x^2-25)=x(x-5)(x+5)}$

Answer 2

 x³ - 25x
resposta: x (x-5) . (x+5)

tirando a prova:
x (x-5) . (x+5)
(x²-5x) . (x+5)
x³ + 5x² +5x² - 25x
x³ - 25x