Find two different state-variable formulations that model the system whose difference equation is given by:

(a) y(k+ 2) + 6y(k+1) + 5y (k)= 2e(k) (b) y(k + 2) + 6y(k+1) + 5y(k) = e(k+1) + 2e(k) (c) y(k + 2) + 6y (k + 1) + Sy(k) = 3e(k+ 2) + e(k + 1) + 2e(k)