Add test for issue 7181. Fixes #7181.
Merge pull request #7695 from debugger22/7181

Add test for issue 7181.
Corrected a typo. Changed an to a
update issue numbers in some tests [skip ci]

See original issue describing the issues migration
at https://github.com/sympy/sympy/issues/7235
Merge pull request #7712 from sarwarc/solvers

Corrected a typo. Changed an to a
Merge pull request #7706 from smichr/issues

update issue numbers in some tests [skip ci]