title: Excel solver won't work when a constraint is unsatisfied in the beginning
body: <p>I have this:</p>
  
  <pre><code>A B C
  2 3 A1+B1
  4 5 A2+B2
  
  constraint_1: A1 + A2 = 5
  constraint_2: B1 + B2 &lt;= 4
  </code></pre>
  
  <p>Objective cell: C3, which is <code>sum(C1,C2)</code>, it should be 0.</p>
  
  <p>When I start with the state above, <code>A1+A2</code> = 6, solver won't work because constraint_1 is broken in the first place (A1+A2=6). Is there a workaround for this?</p>