I need help with these three problems, thank you in advance!

Problem 16: Consider the system 1 G(S) = s? (s+1)(s? +35+2) The system is: ANS: (a) controllable and observable (b) not controllable, not observable (c) controllable but not observable (d) not controllable but observable Problem 17: Consider the system represented by x= Ax + Bu where 1 A= 0 5 0 0 and B= The associated state-transition matrix is: ANS: (a) 0(t,0) =[5t] i 5t (b) 0(t,0) = 0 1 1 5t (c) o(t,0) = 1 1 [i 5t t (d) (t,0) = 0 1 t 0 0 1 Problem 18: What feedback controller could do to a system? ANS: (a) to improve accuracy (b) to improve stability (c) to move closed-loop poles farther to the left (d) to eliminate the effects due to disturbances