> solve({6*p1       -p2                                =5*p+Q/k,        
>                             p1     -6*p2+5*p3             =0,         
>                                           5*p1                  + 4*p3
>             =9*p+Q/k },                       {p1,p2,p3});

            33 p k + Q       55 p k + 3 Q       165 p k + 29 Q
      {p3 = ----------, p2 = ------------, p1 = --------------}
               33 k              55 k               165 k

> collect(%,Q);
> 
> 
> 
> 

                   Q             3 Q            29 Q
            {p3 = ---- + p, p2 = ---- + p, p1 = ----- + p}
                  33 k           55 k           165 k

> 
