SOLUTION: (4+3i)(2-5i)

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Question 554791: (4+3i)(2-5i)
Answer by jim_thompson5910(35256) About Me  (Show Source):
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%284%2B3i%29%2A%282-5i%29 Start with the given expression.


%284%29%282%29%2B%284%29%28-5i%29%2B%283i%29%282%29%2B%283i%29%28-5i%29 FOIL.


8-20i%2B6i-15i%5E2 Multiply.


8-20i%2B6i-15%28-1%29 Replace i%5E2 with -1. Note: i%5E2=-1.


8-20i%2B6i%2B15 Multiply.


23-14i Combine like terms.


So %284%2B3i%29%2A%282-5i%29=23-14i.


So the expression is now in standard form a%2Bbi where a=23 and b=-14


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