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Perform the operation and get your answer in the form a + bi. (3 + 2i)(2 - 4i)
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High School Teacher
Use foil method.
First terms: 3 * 2 = 6.
Outer terms: 3*-4i = -12i
Inner terms: 2i*2 = 4i
Last terms: 2i*-4i = -8i^2
So, we will have:(3 + 2i)(2 - 4i) = 6 - 12i + 4i - 8i^2
Combine like terms, and take note that i^2 = -1.
6 - 12i + 4i - 8i^2 = 6 - 8i -8(-1) = 6 - 8i + 8 = 14 - 8i
Therefore, final answer is 14 - 8i.
Posted by violy on April 13, 2013 at 3:27 AM (Answer #1)
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