title: Math function to remove minus
body: <p>If input value is <code>-0.088</code> and I want take from <code>x = 0.8</code> like this <code>0.8 - -0.088</code> but in result I want get <code>0.712</code> instead of <code>0.888</code> as it would be with minus <code>0.8 - 0.088</code>. </p>
  
  <p>How to remove minus from number without direct string processing, can I use some Math function for such case:</p>
  
  <pre><code>    double x1 = 0.8;
      double x2 = 0.8;
      double a = -0.088;
      double b = 0.088;
  
      x1 = (x1 - a); 
      x2 = (x2 - b); 
  
      Console.WriteLine("0.8 minus -0.088 equals to [ " + x1 + 
                   " ]\r\n0.8 minus 0.088 equals to [ " + x2 + " ]");
  </code></pre>
  
  <p>result:</p>
  
  <pre><code> 0.8 minus -0.088 equals to [ 0.888 ]
   0.8 minus 0.088 equals to [ 0.712 ]
  </code></pre>
  
  <p>desired result:</p>
  
  <pre><code>0.8 minus -0.088 equals to [ 0.712 ]
  0.8 minus 0.088 equals to [ 0.712 ]
  </code></pre>