So I was wondering if there is some commands or/and packages that allows us to hide text (I didn't find an answer here on the site ...) , because I really need it for hiding hints in some math article . Anyway , thanks in advance .
EDIT : I am sorry, I was not clear enough about what I'm looking for ...
exsheetsoranswerswill provide the means, for example – Jul 06 '15 at 13:39