Since different equations of are separated with a comma, it prevents me from using decimal numbers in the systems of equations.

1) I haven't found a separate LaTeX command to type a comma in math mode in order to circumvent this problem. Is there one?
2a) How to modify systeme so that I can input commas as usual?
OR
2b) How to modify systeme so that I can change the argument separator to semicolon (instead of comma)?

MWE:

```
\documentclass{memoir}
\usepackage{systeme}
\begin{document}
\systeme{2x-y=\frac{3}{2},x+2y=6}
\end{document}

```

MNWE:

```
\documentclass{memoir}
\usepackage{systeme}
\begin{document}
\systeme{2x-y=1,5,x+2y=6}
\end{document}

```