For each of the systems of Fig. P5.3-1, express Error! Objects cannot be created from editing field

Question:

For each of the systems of Fig. P5.3-1, express Error! Objects cannot be created from editing field codes. as a function of the input and the transfer functions shown. R(s) R(8) R(s) R(s) T T T (a) T O (d) G(s) H(s) G(s) H(s) G(s) H(s) K T G(s) H(s) T C(s) C(s) C(s) C(s) R(s) T (c) G(s) H(s) T C(8)