correct typo and direct to actual docstring
pass along simplify and iszerofunc flags

If a matrix system, Mx=b, has only Number entries, then M.solve(b)
can be called with no other arguments for a fast solution to that
system. If there are symbolic entries, however, then detecting
zeros in expressions is important. To do that, simplification and/or
zero-detection methods are necessary to obtain meaningful results and
a more robust inversion method that checks for det(M)=0 should be
used.

The gaussj_solve method will only be used on matrices that contain
anything other than Atoms if simplify is False, otherwise, the
need to simplify will signify that the gaussj_solve method should
not be used. If one desires to use gaussj_solve with simplify=True
then that method should be called directly.