title: bash command to sum and print each element of a column and print a new column
body: <p>Which command should I use to sum the values of two specific columns?
  For example, I have the file:</p>
  
  <pre><code>1 4 5 1
  2 3 5 2
  7 8 6 3
  </code></pre>
  
  <p>And I want to sum the second and last columns, to have the following result</p>
  
  <pre><code>1 4 5 1 5
  2 3 5 2 5
  7 8 6 3 11
  </code></pre>
  
  <p>shoud I use awk and bc?
  I have found many examples to sum the entire column...</p>