# How do you multiply (15+3i)(4-15i)?

Aug 24, 2016

$105 - 213 i$ in the standard form

#### Explanation:

First, let's multiply term by term to have:

$60 - 225 i + 12 i - 45 {i}^{2}$

Then, since ${i}^{2} = - 1$, you have

$60 - 213 i + 45$

$105 - 213 i$ in the standard form