SOLUTION: (-7-2i)(6+i)

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Question 284027: (-7-2i)(6+i)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
%28-7-2i%29%2A%286%2Bi%29 Start with the given expression.


%28-7%29%286%29%2B%28-7%29%28i%29%2B%28-2i%29%286%29%2B%28-2i%29%28i%29 FOIL.


-42-7i-12i-2i%5E2 Multiply.


-42-7i-12i-2%28-1%29 Replace i%5E2 with -1. Note: i%5E2=-1 since i=sqrt%28-1%29.


-42-7i-12i%2B2 Multiply.


-40-19i Combine like terms.


So %28-7-2i%29%2A%286%2Bi%29=-40-19i.