Question

descompunand in factori expresia x³-9x obtinem

Answer 1

$x ^{3} - 9x = x \times (x ^{2} - 9) = x \times (x - 3) \times (x + 3)$

Answer 2

X•(x la a 2 - 9)=x•(x-3)•(x+3)

Am aplicat formula

A la a 2 minus b la a doua este egala cu a minus b pe lângă a plus b