A second$-$order system is described by the following state equations:$12()()0$ d x t x t dt $=212()2()3()()$ d x t x t x t r t dt $++=$ Where$1()$x t and$2()$x t are the two state variables and r$($t$)$ denotes the input. The output$1()()$c t x t$=.$ The systems is