Find all possible I/O equations. (left{begin{array}{l}ddot{x}_{1}+2 dot{x}_{1}+frac{3}{5}left(x_{1}-x_{2} ight)=f_{1}(t) 3 ddot{x}_{2}+dot{x}_{2}-frac{3}{5}left(x_{1}-x_{2} ight)=f_{2}(t)^{prime}end{array}, f_{1}(t), f_{2}(t)= ight.) inputs, (x_{2}=)

Find all possible I/O equations.

\(\left\{\begin{array}{l}\ddot{x}_{1}+2 \dot{x}_{1}+\frac{3}{5}\left(x_{1}-x_{2}\right)=f_{1}(t) \\ 3 \ddot{x}_{2}+\dot{x}_{2}-\frac{3}{5}\left(x_{1}-x_{2}\right)=f_{2}(t)^{\prime}\end{array}, f_{1}(t), f_{2}(t)=\right.\) inputs, \(x_{2}=\) output