Include a solution box for the domain of the expression
Remove redundant variable
Split final hint
Typo denomiators -> denominators

fix #43499;

Test plan: check spelling

Auditors: alpert
Remove confusing "times older than" wording

Closes #43492.

Auditors: peter, eater
Get rid of an html-style comment in javascript.

Summary:
Could use //, but the comment is not adding anything new, that I can
see, so I'm happy to just nix it.

This was messing up the python javascript parser I was throwing at
this file.

Test Plan: None

Reviewers: eater, alpert

Reviewed By: alpert

CC: alpert

Differential Revision: http://phabricator.khanacademy.org/D2103
No longer accept answers with a negative denominator
Merge pull request #43528 from petercollingridge/non-neg-denom

No longer accept answers with a negative denominator

fix #43485; and keep Alpert happy.

Test plan: Test exercises http://localhost:8000/exercises/simplifying_rational_expressions_2.html and make sure it still accepts the correct answer whilst rejecting answers with negated denominator and numerator.

Auditors: alpert
Fix to actually select the correct equation

Test plan: as before - check a few example exercises

Auditor: alpert
Merge pull request #43433 from petercollingridge/domain-q

Students must state the domain of simplified expression where necessary.

fix #43504; fix #43362;

Test plan: try a few example exercises (note that 1 of the 3 types don't require a domain to be specified) http://localhost:8000/exercises/simplifying_rational_expressions_3.html

Auditors: eater, alpert, cbhl
Remove menu and autocomplete utils/jquery-ui.js

Summary:
Neither of these appear to be needed directly in khan-exercises, and
they're both served off of the main KA environment. The duplication with
the contents here are causing issues in autocomplete behavior when
exercises are loaded.

There is still an issue of duplication for many of the remaining modules
in jquery-ui.js, such as jquery.ui.core, but that duplication doesn't
appear to be causing issues right now, and are useful for testing
khan-exercises outside of the full KA environment, so I left them in.

Test Plan:
python -m SimpleHTTPServer
navigated to a handful of exercises randomly, made sure they worked
ack '\.autocomplete\('  # no results
ack '\.menu\('  # no results

Reviewers: eater

CC: alpert

Differential Revision: http://phabricator.khanacademy.org/D2109
Remove ?test mode since no one uses it

Auditors: eater, cbhl
Added naming_polynomials to address SB tags HS.1.D.1.SR.2-3. Also changed randRangeUnique to include the entire range.
Merge branch 'master' of https://github.com/Khan/khan-exercises into backup
Merge branch 'backup'
Merge branch 'naming'
Fixed final hints in naming_polynomials