title: Add unknown variables to Excel
body: <p>Here is a screenshot from my TI CAS:
  <a href="https://i.stack.imgur.com/rjxTI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rjxTI.png" alt="TI-CAS"></a></p>
  
  <p>I would like to do the same into an Excel file. I want to put "x" in a cell and make other cells compute with it.</p>
  
  <p>Is there a way to add "unknown variables" to Excel? I don't want it to solve anything, but I need to have values like: 0.06*x+66000</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>For example, if D2 = x and E3 = 2, I want to have "x-2" if I enter "=D2-E3" in a cell.</p>
  
  <p><strong>EDIT</strong></p>
  
  <p>The "x" must be evaluate, not only concatenate. It must simplify the next equation like shown in the screenshot. For example, if you have: <code>A1: x-2</code> and <code>A2: 3</code>, if you do: <code>A3: =A1*A2</code> you should have: <code>3x-6</code>.</p>