# Multiplying Complex Numbers

Discussion in 'Other Pre-University Math' started by nycmathguy, Sep 14, 2021.

1. ### nycmathguy

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Section 2.4
32 & 34

Question 32

(7 - 2i)(3 - 5i)

21 - 35i - 6i + 10i^2

21 - 41i + 10(-1)

21 - 41i - 10

11 - 41i

Question 34

-8i(9 + 4i)

-72i - 32i^2

-72i - 32(-1)

-72i + 32

Switch the terms.

32 - 72i

You say?

nycmathguy, Sep 14, 2021
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2. ### MathLover1

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perfect

MathLover1, Sep 14, 2021
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3. ### nycmathguy

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Good chapter so far. Keep in mind that precalculus is a review for me, a return to MA172.

nycmathguy, Sep 15, 2021
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