# How do you multiply (-4i)(-8-8i)(1-8i)?

Mar 14, 2017

$224 i - 288$

#### Explanation:

Distribute $\left(8 - 8 i\right) \left(1 - 8 i\right)$ using the FOIL method, say. Then multiply the result by $\left(- 4 i\right)$

$\textcolor{\mathmr{and} a n \ge}{\text{Reminder: }} {i}^{2} = {\left(\sqrt{- 1}\right)}^{2} = - 1$

$\Rightarrow \left(8 - 8 i\right) \left(1 - 8 i\right)$

$= 8 - 64 i - 8 i + 64 {i}^{2}$

$= - 72 i - 56$

$\Rightarrow \left(- 4 i\right) \left(- 72 i - 56\right)$

$= 288 {i}^{2} + 224 i$

$= 224 i - 288$