From: drhuang57@gmail.com   
      
   problem should be marked as"not solved" when its solution cannot give 0 in the   
   left hand side of equation.   
      
   http://www.mathhandbook.com/input/?guess=+dsolve%28diff%28y%28x%   
   9%2Cx%29-f%28a*x%2Bb*y%28x%29%29+%3D+0%2Cy%28x%29%29   
      
   here is link for problems 84. just copy problem in "maple input" to   
   mathHandbook.com, then hit the Enter key in the keyboard.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)