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

Apr 15, 2018

The answer is $- 8 i + 32$.

#### Explanation:

Simplifying $4 i \left(- 2 - 8 i\right)$:

First, factor out the $4 i$: $- 8 i - 32 {i}^{2}$.

Because $i$, an imaginary number, is equal to $\sqrt{- 1}$, ${i}^{2}$ (or ${\left(\sqrt{- 1}\right)}^{2}$ should be $- 1$.

Therefore, you can substitute in $- 1$ for ${i}^{2}$. Therefore your answer is $- 8 i - \left(32 \cdot - 1\right)$. This simplifies to your final answer, $- 8 i + 32$.

Hope this helps!