# How do you factor x^3-2x-21?

$\left({x}^{2} + 3 x + 7\right) \left(x - 3\right)$
${x}^{3} - 2 x - 21 = {x}^{3} - 3 {x}^{2} + 3 {x}^{2} - 9 x + 7 x - 21 = {x}^{2} \left(x - 3\right) + 3 x \left(x - 3\right) + 7 \left(x - 3\right) = \left({x}^{2} + 3 x + 7\right) \left(x - 3\right)$[Ans]