Changing the system representation using symbolics

I currently have a gray model in the form of a state space with 8 states 1 input and 1 output and 10 parameters (symbols) which have to be estimated. What i want to do is write a single state as a function of the input and parameters only. Is there a way to do this in Matlab or do i have to convert all equations to the Laplace domain and substitute all equations by hand?

Thanks