title: Sum all values in all rows using array formula
body: <p>I would like an array formula to sum up columns G26:AD per row, since the amount of rows is dynamic.</p>
  
  <pre><code>=ArrayFormula(sum(G26:26)) 
  </code></pre>
  
  <p>does not work. I tried using MMULT but did not manage to get it working:</p>
  
  <pre><code>=MMULT(G26:26,TRANSPOSE(ARRAYFORMULA(COLUMN(G26:26)^0)))
  </code></pre>
  
  <p>Any other ideas?</p>