Question

Please help with 29. Perform the indicated operation and express result as a simplified complex number

Answer 1

Solution

29. (3+4i)(3-4i)

We can operate and we have this:

$3\cdot3-3\cdot4i+3\cdot4i+(4i)(-4i)$

Solving we got:

$9-12i+12i-16i^2$

We also know that:

$i^2=-1$

Then we have:

$9-16(-1)=9+16=25$

Then the final answer is 25