Factor x^3+x-3x^2-3

$x^{3} + x - 3 x^{2} - 3$

Reorder terms.

$x^{3} - 3 x^{2} + x - 3$

Factor out the greatest common factor from each group.

Group the first two terms and the last two terms.

$(x^{3} - 3 x^{2}) + x - 3$

Factor out the greatest common factor (GCF) from each group.

$x^{2} (x - 3) + 1 (x - 3)$

Factor the polynomial by factoring out the greatest common factor, $x - 3$ .

$(x - 3) (x^{2} + 1)$