title: How to show math equations in general github's markdown(not github's blog)
body: <p>After investigating, I've found mathjax can do this. But when I write some example in my markdown file, it doesn't show the correct equations:</p>
  <p>I have added this in the head of markdown file:</p>
  <pre class="lang-html prettyprint-override"><code>&lt;script type=&quot;text/javascript&quot; src=&quot;http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=default&quot;&gt;&lt;/script&gt;
  </code></pre>
  <p>And type the mathjax statement:</p>
  <pre><code>\(E=mc^2\)，$$x_{1,2} = \frac{-b \pm \sqrt{b^2-4ac}}{2b}.$$
  </code></pre>
  <p>But github shows nothing for the math symbols! Please help me, thanks!
  Tell me how to show math symbols in github markdown pages.</p>