Before you can find an answer, you generally have to know
what the question is, and you may not be there yet.
One thing I can see that you might want to “do” with this equation is
find out what number ‘ i ‘ must be in order to make the equation true.
Here’s how you might do that:
You said 3 + 10i = 4i – 18
Lets subtract 4i
from each side: 3 + 6i = – 18
Now subtract 3
from each side: 6i = – 21
Divide each side by 6 : i = – 21/6 or -(3 and 1/2) .