# How do you factor by grouping x^3-12-3x^2+4x?

Apr 9, 2015

Have a look:
Collect between the 1st and 3rd term and between 2nd and 4th:

Apr 9, 2015

${x}^{3} - 12 - 3 {x}^{2} + 4 x$
can be re-grouped as
$\left({x}^{3} - 3 {x}^{2}\right) + \left(4 x - 12\right)$
which can then be factored as
$\left({x}^{2}\right) \left(x - 3\right) + \left(4\right) \left(x - 3\right)$
then combining the common factor from each term
$\left({x}^{2} + 4\right) \left(x - 3\right)$