SOLUTION: (-7+6i)(-7-5i)

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Question 316038: (-7+6i)(-7-5i)
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
%28-7%2B6i%29%2A%28-7-5i%29 Start with the given expression.


%28-7%29%28-7%29%2B%28-7%29%28-5i%29%2B%286i%29%28-7%29%2B%286i%29%28-5i%29 FOIL.


49%2B35i-42i-30i%5E2 Multiply.


49%2B35i-42i-30%28-1%29 Replace i%5E2 with -1. Note: i%5E2=-1.


49%2B35i-42i%2B30 Multiply.


79-7i Combine like terms.


So %28-7%2B6i%29%2A%28-7-5i%29=79-7i.