Mathjax not rendering TEX formulas dynamically from PHP/Ajax

var questions = {"ques_id":"1","question":"<p><span class=\\\"math-tex\\\">\\\\(x = {-b \\\\pm \\\\sqrt{b^2-4ac} \\\\over 2a}\\\\)<\/span>&nbsp; &nbsp;Test Question new with mathjax<\/p>","ques_type":"text_based_questions","correctAnswer":3,"choices":[{"option_id":"1","value":"Option A"},{"option_id":"2","value":"Option B"},{"option_id":"3","value":"Option C"},{"option_id":"4","value":"OPtion D"}]};

$('#test-question').html(questions.question);
MathJax.Hub.Queue(["Typeset",MathJax.Hub, 'test-question']);

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width">
    <script type="text/x-mathjax-config">
      MathJax.Hub.Config({
        showProcessingMessages: false,
        tex2jax: { inlineMath: [['$','$'],['\\(','\\)']] }
      });
    </script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-MML-AM_HTMLorMML">
    </script>
    </head>
 <body>
    <h5 class="border-bottom">Instructions: Read the question, work out your answer and select the best option.</h5>
    <p><span class="math-tex">\( \left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right) \)</span></p>
  <div class="question" id="test-question"></div>
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js"></script>
  </body>
</html>