# How do you simplify 8(-2i)(-5-4i)?

Dec 3, 2016

$- 64 + 80 i$

#### Explanation:

Multiply 8 and 2i together and distribute the bracket with this product.

$\Rightarrow 8 \left(- 2 i\right) \left(- 5 - 4 i\right)$

$= - 16 i \left(- 5 - 4 i\right) = 80 i + 64 {i}^{2}$

$\textcolor{\mathmr{and} a n \ge}{\text{Reminder}} \rightarrow {i}^{2} = - 1$

$\Rightarrow 80 i + 64 {i}^{2} = - 64 + 80 i$