# How do you simplify -6i(8-6i)(-8-8i)?

Sep 9, 2016

$- 96 + 672 i$

#### Explanation:

Before multiplying by - 6i , expand the brackets, using for example, the FOIL method.

$\Rightarrow \left(8 - 6 i\right) \left(- 8 - 8 i\right) = - 64 - 64 i + 48 i + 48 {i}^{2}$

$\textcolor{\mathmr{and} a n \ge}{\text{Reminder }} \textcolor{red}{\overline{\underline{| \textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{{i}^{2} = {\left(\sqrt{- 1}\right)}^{2} = - 1} \textcolor{w h i t e}{\frac{a}{a}} |}}}$

$\Rightarrow \left(8 - 6 i\right) \left(- 8 - 8 i\right) = - 16 i - 112$

and $- 6 i \left(- 16 i - 112\right) = 96 {i}^{2} + 672 i = - 96 + 672 i$