title: Reversing a math formula
body: <p>I found this formula to calculate mortgage payments</p>
  
  <p>The interest rate is <strong>IntRate</strong>, <strong>Pa</strong> represents the payment, <strong>PrValue</strong> is the present value of the loan, and <strong>Period</strong> is the number of years the money is borrowed.</p>
  
  <pre><code>Pa = (PrValue * IntRate) / (1 - Math.pow (1 + IntRate, - (Period * PPay)))
  </code></pre>
  
  <p>What I would like to do is get the value of <strong>isPrValue</strong></p>
  
  <pre><code>isPrValue = ?
  </code></pre>
  
  <p><a href="http://www.1stop-mortgagecalculator.com/mortgage-calculator-code.htm#Canadian-Mortgage-Formula" rel="nofollow">source</a></p>