This might seem as a stupid question but I would like to upload a word document as an answer to a question. I can convert the document to html and copy its contents but most of the formula disappear when pasting into the stack exchange answer box. I dont have a website, which could refer the interested people to an URL. I do have Google Drive and a shared folder, but how can I reference this folder in the answer box.
We generally like answers to be written using the markup facilities provided so they are searchable. That's why we deprecate the posting of images containing the working. If your answer was a screengrab of the document or just a link to the document it would not be very popular.
Whenever I want to compose a long answer I generally write in Word then copy and paste into this site. However I will have already used MathJax to format equations. I'm guessing you've used the Word equation editor or something similar for equations. In that case the only option is to rewrite the equations using MathJax.
If redoing the equations is impossibly time consuming then I'm afraid the best option is not to answer at all.
A last desparate option might be to post a link to the document in the chat room and ask if anyone would be interested in converting the equations to MathJax. If it's one of the areas I'm particularly interested in (e.g. GR) then I might be willing.