Verified answer

[tex] {x}^{3} + 3 {x}^{2} - x - 3 = ( {x}^{3} + 3 {x}^{2} ) + ( - x - 3) = \\ = {x}^{2} (x + 3) - (x + 3) = ({x}^{2} - 1)(x + 3)[/tex]

Ответ: 1)