title: Adding a Third column of data in Mathematica
body: <p>I have a very large table of data something like:</p>
  
  <pre><code>lista = {{2,8},{3,4},{5,2}..}
  </code></pre>
  
  <p>I would like to add x to every element so it would be</p>
  
  <pre><code>lista ={{x,2,8},{x,3,4},{x,5,2}.....}
  </code></pre>
  
  <p>This seems to me like it should be rather trivial but I have not been able to find a solution.</p>
  
  <p>I would appreciate any help.</p>