Basically, you just have to distribute, while remembering that i^2 = -1. So:
[tex]4i(6-2i)[/tex]
Turns into:
[tex](4i*6)-(4i*2i)[/tex]
Which is easy:
[tex]24i - 8i^2[/tex]
We figured out that i^2 = -1, so:
[tex]24i-8(-1) = 24i+8[/tex]
And that's your answer!
