Simplify exponential expression



Hi, just a simple question ... could you please tell me how to group first and 
second term as well as third and fourth of the following expression 

(%i1) 2*exp(-3*t/2)*
(18*sinh(sqrt(5)*t/2)/sqrt(5)-6*cosh((sqrt(5)*t/2)))+12,exponentialize,expand;

Thanks

Regards
Dionisio