# How do you factor by grouping  3x^4+6x^3-6x-12 ?

You can collect $3 x$ from the first and third term and $6$ from the second and fourth to get:
$3 x \left({x}^{3} - 2\right) + 6 \left({x}^{3} - 2\right) =$ now collect $\left({x}^{3} - 2\right)$ and get:
$= \left({x}^{3} - 2\right) \left(3 x + 6\right)$