# Math Help - complex multiplication

1. ## complex multiplication

COMPLEX NUMBERS

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z = (9 - 7i)
Find the product of z and its complex conjugate
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Huh?!

COMPLEX NUMBERS

---
z = (9 - 7i)
Find the product of z and its complex conjugate
---

Huh?!
This is a rule
Product of,
$a+bi$
With conjugate,
$a-bi$
Is, (by just expanding)
$a^2+b^2$
Thus,
$9^2+7^2$