title: Adding string after a specific string using sed Unix
body: <p>I have a string in a file like this:</p>
  
  <pre><code>"Value1=[random number]"
  </code></pre>
  
  <p>After this string I want to add another string, specifically:</p>
  
  <pre><code>"Value2=100"
  </code></pre>
  
  <p>If I try to use:</p>
  
  <pre><code>sed  '/Value1=/a Value2=100' myfile.txt
  </code></pre>
  
  <p>It will fail because I have not included the fact that Value1=[some random number].</p>
  
  <p>How do I add the condition that Value1=random number and Value2 should be added to this string?</p>