# How do you factor by grouping 4b^2+4bc+c^2-16?

$\left(2 b + c + 4\right) \cdot \left(2 b + c - 4\right)$
$\textcolor{red}{4 {b}^{2} + 4 b c + {c}^{2}} - \textcolor{b l u e}{16}$
$\textcolor{w h i t e}{\text{XXXX}}$$\textcolor{red}{{\left(2 b + c\right)}^{2}} - \textcolor{b l u e}{{4}^{2}}$
$\textcolor{w h i t e}{\text{XXXX}}$$\left(2 b + c + 4\right) \cdot \left(2 b + c - 4\right)$