problem solving radical equations



Trying to solve a system of equations with radicals, i get an error message:

(%i1) solve([x+3*y=5,sqrt(x+y)-1=y]);

`algsys' cannot solve - system too complicated.
 -- an error.  Quitting.  To debug this try debugmode(true);


Even trying to solve a very simple radical equation, i get a wrong answer:

(%i3) solve(sqrt(x+1)=9+x);

(%o3)                        [x = sqrt(x + 1) - 9]



IS there a way to handle radical equations? maybe some external package?

Anyways, regardless of external packages, i consider that the solve command 
shoud handle these kind of equations, since the method of sqaring both sides 
of the equality is not what i would call sophisticated. I am trying to 
introduce maxima in my high school classes, and my students would laugh if 
they find that they know how to solve these systems better than the computer.




Miguel Angel Marco Buzunariz.
Departamento de matem?ticas.
Universidad de Zaragoza.