I'm trying to get a question of the form
|ax+b|<9
(solve for x) to work. However, I'm not sure how get this to work very well. I'm looking at some college of Idaho questions by RA Cruz, and these work very nicely with contextInequalitiesAllowStrings.pl, which is a macro that uses the contextInequalities and adds the ability to answer with "none" and "all real" or something to that effect (though I'm not sure that it every got up and running completely. This page http://webwork.maa.org/pod/NationalProblemLibrary_TRUNK/macros/CollegeOfIdaho/contextInequalitiesAllowStrings.pl.html says that the "none" part doesn't work, but that's a whole different issue).
Initially I thought I could use it, or at least contextInequalties, but to my knowledge, I'm not allowed to have variables in them, like this "-5b < x <= 8b". First of all, is this the case?
If it is, this is really tragic, because I'd like to have the capability in the question of the nature of the solution changing based on the seed - that is, for some, there would be no solution, for some, there would only be one equality describing x, and for some there would need to be two inequalities describing x. If I had an answering system like the University of Rochester questions that I'm looking at, "
To say that ∣∣∣x−72∣∣∣≤6 is the same as saying x is in the closed interval [A,B]
What is A, and what is B?"
This doesn't work nearly as well in terms of the flexibility in the nature of answers that I'd like to have. I theoretically could have a large series of if statements determining the nature of the answer ans formatting the question in three different ways for each kind of answer, and I'll probably end up doing that if it turns out that no one has any very bright ideas on the subject.
Does anyone have any very bright ideas on the subject?
(I'd provide some code, but there really isn't any specific problem I'm having, so it doesn't make too much sense to post anything. If someone requests some I'll post it.)