It is important to clarify upfront: in the mainstream mathematical software ecosystem (such as MATLAB, Maple, Mathematica, or even niche CAS tools like SageMath or GeoGebra).
The name "Algebrator" historically refers to an older algebra tutorial software (from the company Softmath ), but its last widely known versions were in the 2.x–3.x range, and it was discontinued years ago. There is no verified public release of "Algebrator 5.1." Algebrator 5.1