You can apply almost all arithmetic operations to dynamic system models, including those shown below.
Right matrix divide
Left matrix divide
Powers of a dynamic system model (as in s^2)
In some cases, you might obtain better results using model interconnection commands, such as feedback or connect, instead of model arithmetic. For example, the command T = feedback(H1,H2) returns better results than the algebraic expression T = H1/(1+H2*H1). The latter expression duplicates the poles of H1, which inflates the model order and might lead to computational inaccuracy.