error - system too complex



when i typed the following commands on the maxima command line ,

Maxima restarted.
(%i1) T:matrix([3,45,6,7,8]);

(%o1)                         [ 3  45  6  7  8 ]
(%i2) t:matrix([0,3,48,54,61,69]);
(%o2)                      [ 0  3  48  54  61  69 ]
(%i3) algsys([5/N-sum(F*%
E^(-F*t[1,i])*T[1,i],i,1,5)=0,5/F-sum(t[1,i],i,1,6)-sum(F*n*t[1,i]+%
E^(-F*t[1,i])*T[1,i],i,1,5)=0],[N,F]);

i got the follwing error : 

ALGSYS cannot solve - system too complicated.
 -- an error.  Quitting.  To debug this try DEBUGMODE(TRUE);

Is there another way to solve this system using maxima ? if this system
can't be solved using it  , what other CAS could I use  ?