Answer:
12y +16yi
Step-by-step explanation:
The thing about complex numbers is that you can treat them as binomials and use all of the things you know about multiplying and factoring polynomials.
Here, we assume you have ...
(5 +2yi)(4 -3i) -(5 -2yi)(4 -3i)
The factor (4 -3i) can be factored out, so you have ...
= ((5 +2yi) -(5 -2yi))(4 -3i)
= (4yi)(4 -3i)
= 16yi -12yi²
At this point, the definition of i comes into play, and you replace i² with -1.
= 12y +16yi
