Question

Simplify the expression (7 + 9i)(8 - 10i)

Answer 1

The simplified expression of (7 + 9i)(8 - 10i) is 146 + 2i

How to simplify the expression?

The expression is given as:

(7 + 9i)(8 - 10i)

Expand the bracket

7 * 8 + 9i * 8 -7 * 10i - 9i * 10i

Evaluate the products

56 + 72i -70i - 90(i²)

Evaluate the difference

56 + 2i - 90(i²)

In complex numbers;

i² = -1

So, we have:

56 + 2i - 90(-1)

Evaluate

56 + 2i + 90

Add the like terms

146 + 2i

Hence, the simplified expression of (7 + 9i)(8 - 10i) is 146 + 2i

Read more about complex numbers at:

brainly.com/question/10662770

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