title: Division equation in latex
body: <p>I googled, but the only examples i found with frac was with numbers or simple variables, no one near with alpha, beta or pi.</p>
  
  <p>Can somebody please help me with this equation? Or provide an example using frac with alpha, beta and pi?</p>
  
  <p>Here is my equation that gives me error.</p>
  
  <pre><code>\textit{$\gamma_{i}$(t)$\equiv$ P($X_{t}$ = i $\vert$ Y,$\theta$)} = \frac{$\alpha_{i}$ (t) $\beta_{i}$ (t)} {$\sum\limits_{j=1}^{N}$ $\alpha_{j}$ (t) $\beta_{j}$(t)}
  </code></pre>
  
  <p>Thanks in advance.</p>