It's difficult to typeset mathematics in raw text, so I try to design
problems that can be done with a minimum of nasty typesetting. Obviously
it's impossible to avoid matrices, but all problems are intended to be
doable without resort to fractions or other constructs that are difficult
to typeset. If you think that a problem can't be done without a lot of
fractions or other nastiness, it's possible that you're approaching it
wrong, but it's also possible that I messed up. Tell me!