MathJax
Using MathJax version 3
If you write your own HTML (directly or via a template/theme engine), you can include MathJax by adding this snippet to your page:
When \(a \ne 0\), there are two solutions to \(ax^2 + bx + c = 0\) and they are
\[x = {-b \pm \sqrt{b^2-4ac} \over 2a}.\]