# How do you factor x^2+-16?

$\left(x + 4\right) \left(x - 4\right) = {x}^{2} - 16$
$\left(x + 4 i\right) \left(x - 4 i\right) = {x}^{2} + 16$
$\left(x + y\right) \left(x - y\right) = {x}^{2} - {y}^{2}$
$y = b i \setminus R i g h t a r r o w \left(x + b i\right) \left(x - b i\right) = {x}^{2} - {\left(b i\right)}^{2} = {x}^{2} + {b}^{2}$