# How do you simplify (-7i)(4i)(3-6i)?

May 7, 2018

$84 - 168 i$

#### Explanation:

multiply all the terms together.

you can start by multiplying $- 7 i$ by$4 i$:

$- 7 \cdot 4 = - 28$

$i \cdot i = {i}^{2} = - 1$

$= 7 i \cdot 4 i = - 28 \cdot - 1$

$= 28$

$\left(- 7 i\right) \left(4 i\right) \left(3 - 6 i\right) = 28 \left(3 - 6 i\right)$

$28 \cdot 3 = 84$

$28 \cdot - 6 i = - 168 i$

$28 \left(3 - 6 i\right) = 84 - 168 i$

hence, $\left(- 7 i\right) \left(4 i\right) \left(3 - 6 i\right) = 84 - 168 i$

$84 - 168 i$ would be the expression in rectangular form.