# How do you factor by grouping x^3 + (2)x^2 + (4)x + 8?

${x}^{3} + 2 {x}^{2} + 4 x + 8 = {x}^{2} \left(x + 2\right) + 4 \left(x + 2\right) = \left(x + 2\right) \left({x}^{2} + 4\right)$
and we can not proceed further because the factor ${x}^{2} + 4$ can't be factored in $\mathbb{R}$.