please explain how to convert this to the closed loop transfer function form

I Consider the two equivalent systems shown below. (a) Determine G(s) and H(s) of the block diagram shown in fig (b) that are equivalent to those of the block diagram in fig (a) (b) Determine Y(S)/R(S) (c) Find y(t) if r(t)=u(t); u(t) being step input that will make r(t) to be step response. R(s) G(s) H(s) nect to the role (6) Block diagram Equivalence ale certain control system has a block diagram structure shown below: R(s) — *0- ti Y(s) 5 + 1 sis + 4 (a) Find the range of K for the stable closed loop system. (b) When the system is marginally stable, find the frequency of oscillations. Equations