# How do you factor by grouping x^3 - 8x^2 - 7x + 56?

Jun 28, 2018

$\left({x}^{2} - 7\right) \left(x - 8\right)$

#### Explanation:

We have the following:

$\textcolor{\lim e}{{x}^{3} - 8 {x}^{2}} \textcolor{p u r p \le}{- 7 x + 56}$

We can factor an ${x}^{2}$ out of the green terms, and a $- 7$ out of the purple terms. Doing this, we get

$\textcolor{\lim e}{{x}^{2}} \textcolor{b l u e}{\left(x - 8\right)} \textcolor{p u r p \le}{- 7} \textcolor{b l u e}{\left(x - 8\right)}$

Both terms have a $x - 8$ in common, so we can factor that out to get

$\left({x}^{2} - 7\right) \left(x - 8\right)$

Hope this helps!