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Please help me with this question

Find the product of (6-10i) and it’s conjugate.

Product = ?

FYI: the answer is not 6-10i or 6+10i

2 Answers

4 votes

Answer:

136

Explanation:

(6-10i)(6+10i)

36 +60i - 60i - 100i²

36 - 100i² (i² = -1)

36 + 100

136

User Matuku
by
4.8k points
3 votes

Answer: 136

Explanation:

First, we need to find the conjugate before we can find the product of the conjugate and 6-10i.

The conjugate is the binomial with an opposite sign.

6+10i

Now that we have our conjugate, we can find the product.

(6-10i)(6+10i) [distribute the factors, FOIL method]

36+60i-60i-100i² [combine like terms]

36-100i² [i²=-1]

36-100(-1) [multiply and subtract]

36+100=136

Our product is 136.

User Ralph Versteegen
by
4.9k points