Question

(7+9i)*(7-9i) Сколько будет?

Answer 1

Вот решение для твоего примера

Answer 2

=49-81 i²=49+81=130, i²= - 1

Answer 3

To calculate the product of two complex numbers, you can use the FOIL method (First, Outer, Inner, Last). Let's apply it to the given expression:

(7 + 9i) * (7 - 9i)

FOIL:

First: 7 * 7 = 49 Outer: 7 * (-9i) = -63i Inner: 9i * 7 = 63i Last: 9i * (-9i) = -81i^2

Now, remember that i^2 is equal to -1. So, we can simplify the expression further:

-81i^2 = -81 * (-1) = 81

Now, add up all the parts:

(7 + 9i) * (7 - 9i) = 49 + (-63i) + 63i + 81

The imaginary terms (-63i and 63i) cancel each other out, leaving us with:

(7 + 9i) * (7 - 9i) = 49 + 81

Finally, sum the real and imaginary parts:

(7 + 9i) * (7 - 9i) = 130

So, the result of the given expression is 130.