please please...need help in solving equation usin matlab

Zthjsl(timel)=(Rjs1*(1-exp(-timel/taujs1)))+(Rjs2*(1-exp(-timel/taujs2)))+(Rjs3*(1-exp(-timel/taujs3)))+(Rjs4*(1-exp(-timel/taujs4)))+(Rjs5*(1-exp(-timel/taujs5)))+(Rjs6*(1-exp(-timel/taujs6)));

Zthjsh(timel)= Rjs1*(1-exp(-(T-timel)/taujs1)) + Rjs2*(1-exp(-(T-timel)/taujs2)) + Rjs3*(1-exp(-(T-timel)/taujs3))+ Rjs4*(1-exp(-(T-timel)/taujs4)) + Rjs5*(1-exp(-(T-timel)/taujs5)) + Rjs6*(1-exp(-(T-timel)/taujs6)) ;

Zthsal(timel)= Rsa*(1-exp(-timel/tausa));

Zthsah (timel)= Rsa*(1-exp(-(T-timel)/tausa));

Thetal(timel) = plossl*(Zthjsl(timel) + Zthsal(timel));

Thetah(timel) = plossh*(Zthjsh(timel)+ Zthsah(timel));

Thetal(timel)=Thetah(timel);

only one unknown is there timel.i tried but i could not come up with a solution how to get the values of timel if all other parameters are specified