12448: make test more robust
12448: make test more robust

Regarding the test added:

    The soutions should be the same if they go through the same
    solution path. Although the two solutions differ in terms of
    how a minus sign is distributed, the op count is the same.
    The op count is significantly different if two different paths
    are taken when solving the system of equations. The times
    taken to solve each system should be similar, too. Before this
    PR, the time to solve the 3 eqn system in terms of functions took
    about 20 times longer to solve than the system written in terms
    of symbols.

kaushik94/sympy,kaushik94/sympy,kaushik94/sympy