# How do you simplify (3 + 2i)(2 − i) and write in a+bi form?

##### 1 Answer
Dec 10, 2015

$8 + i$

#### Explanation:

You can simply multiply the two parenthesis as you do with normal number, and then remember that you can sum immaginary numbers (e.g. $3 i + 5 i = 8 i$) and that ${i}^{2} = - 1$. So, you have

$\left(3 + 2 i\right) \left(2 - i\right) =$

$6 - 3 i + 4 i - 2 {i}^{2} =$

$6 + i - 2 \left(- 1\right) =$

$6 + i + 2 = 8 + i$