How do you simplify #(3+ 3i ) - ( 6- 9i )#?

1 Answer
Dec 1, 2016

#12i - 3#

Explanation:

First, expand the terms in parenthesis. Take care when expanding a term with a negative sign to ensure your signs are correct - "-" x "-" is a "+":

#3 + 3i - 6 + 9i#

Next rearrange to get like terms together:

#3i + 9i + 3 - 6#

Now combine like terms to simplify:

#(3 + 9)i + (3 - 6)#

#12i - 3#