title: Matlab: Finding two unknown constants/parameters in an equation
body: <p>I've read up on fsolve and solve, and tried various methods of curve fitting/regression but I feel I need a bit of guidance here before I spend more time trying to make something work that might be the wrong approach.</p>
  
  <p>I have a series of equations I am trying to fit to a data set (x) separately:</p>
  
  <p>for example:</p>
  
  <blockquote>
  <pre><code>(a+b*c)*d = x
  a*(1+b*c)*d = x
  </code></pre>
    
    <p>x = 1.9248
        3.0137
        4.0855
        5.0097
        5.7226
        6.2064
        6.4655
        6.5108
        6.3543
        6.0065</p>
    
    <p>c=  0.0200
        0.2200
        0.4200
        0.6200
        0.8200
        1.0200
        1.2200
        1.4200
        1.6200
        1.8200</p>
    
    <p>d = 1.2849
        2.2245
        3.6431
        5.6553
        8.3327
       11.6542
       15.4421
       19.2852
       22.4525
       23.8003</p>
  </blockquote>
  
  <p>I know c, d and x - they are observations. My unknowns are a and b, and should be constant.</p>
  
  <p>I could do it manually for each x observation but there must be an automatic and far superior way or at least another approach.</p>
  
  <p>Very grateful if I could receive some guidance. Thanks for the time!</p>