I'm been trying this kind of thing, since  org-export-html-mathjax-options doesnt have anything to configure. 

#+LATEX_HEADER: \usepackage{amsmath}

#+MATHJAX: align:"left" mathml:t path:"C:\Users\JohnT\Desktop\mj\MathJax.js"

#+BEGIN_HTML

<script type="text/javascript"

   src="C:\Users\JohnT\Desktop\mj\MathJax.js?config=TeX-AMS-MML_SVG-full,"C:\Users\JohnT\Desktop\mj\config\TeX-AMS-MML_SVG-full.js">

</script>

<script type="text/javascript"

MathJax.Ajax.loadComplete("C:\Users\JohnT\Desktop\mj\config\TeX-AMS-MML_SVG-full.js");

</script>

#+END_HTML

#+TEX

$$\begin{matrix}

  a & b & c \\

  d & e & f \\

  g & h & i

 \end{matrix}$$

#+END_TEX