Why Symbolic Solve of multivariable linear equations return unwanted variables as answer

Hi. I recently use MATLAB to help me solving my math. This is the script

clc,clear
syms kl kw kd l w F uu vv
Eq1= (kl*(l^2+w^2)+kd*l^2)*uu-(2*kd*l*w)*vv==F*(l^2+w^2)/2;
Eq2= (kd*w*l)*uu-(2*kd*w^2+2*kw*(l^2+w^2))*vv==0;
S=solve([Eq1, Eq2], [uu, vv]);

Anyway, the solver return

S = 
   l: [2x1 sym]
  uu: [2x1 sym]
  vv: [2x1 sym]
   w: [2x1 sym]

and S.uu, S.vv are zeros vectors. I using MATLAB 2012a

Answer 1

[Walter Roberson]

S=solve(Eq1, Eq2, uu, vv);