2i/4-8i

2i/4-8i * (4+8i)/(4+8i)

then i multiplied the top and bottom and got

8i/ 4^2 + 16i/8^2

8/80 + 16i/80

reduce to
4/5 + 2i

is this correct

You started off ok, but then ...

2i/(4-8i) * (4+8i)/(4+8i)
= (8i + 16i^2)/(16 - 64i^2)
= (8i + 16i^2)/(80)
= (i - 2)/10
or
i/10 - 1/5