Sorry for the straightforward question but you're all the best people for me to ask.
My question is about style and best shown with an example.
Consider:
$$\frac{3-5i}{1+3i}$$
Is it acceptable to write the answer as:
$$\frac{-6-7i}{5}$$
Or must real and imaginary parts always be stated separately:
$$-\frac{6}{5} - \frac{7i}{5}$$
Or indeed should the $i$ be separate too?
$$-\frac{6}{5}-\frac{7}{5}i $$
Thanks.