title: Mathematica - Solve equation as an expression of two variables
body: <p>Simple question, all I want to do is have Solve[] work in a way that instead of solving for a single variable (eg. Vo) it solves for the expression Vo/Vi. In all cases this just equates to dividing both sides by Vi, as it'll cancel out on the RHS anyway, curious if there's a quick way to do it though.</p>
  
  <p>Thanks</p>
  
  <p>EDIT: Here's the code</p>
  
  <pre><code>vd = 0 - V1;
  VL = Solve[(V1 - Vi)/R1 + (V1 - Vo)/R2 == 0, V1][[All, 1, 2]][[1]];
  VR = Solve[(Vo - V1)/R2 + (Vo - (AO*vd))/RO == 0, V1][[All, 1, 2]][[1]];
  Av = Solve[VL == VR, Vo][[All, 1, 2]][[1]];
  Av = Av/Vi //I add this to remove the Vi
  </code></pre>
  
  <p>Basically I want it to solve for Vo/Vi, to automatically remove the Vi from the RHS...</p>