# How do you add (2i + 9) + ( 8- 3i )?

Jan 13, 2018

$17 - i$

#### Explanation:

$\left(2 i + 9\right) + \left(8 - 3 i\right)$

expand brackets:

$2 i + 9 + 8 - 3 i$

collect like terms:

$9 + 8 + 2 i - 3 i$

$17 - i$
[this corresponds to $a + b i$ form, where $b = - 1$]