# Complex Addition/Examples/(3 + 2i) + (-7 - i)

## Example of Use of Complex Addition is Commutative

$\paren {3 + 2 i} + \paren {-7 - i} = -4 + i$

## Proof

 $\displaystyle \paren {3 + 2 i} + \paren {-7 - i}$ $=$ $\displaystyle \paren {3 + \paren {-7} } + \paren {2 + \paren {-1} } i$ Definition of Complex Addition $\displaystyle$ $=$ $\displaystyle -4 + i$

$\blacksquare$