Untitled

clc 
clear all;
close all;
num1=[1];
den1=[1 0 4]
sys1=tf(num1, den1)
num2=[6]
den2=[0 1 0]
sys2=tf(num2, den2)
result= feedback(sys2,sys1+1)
num3=[0 0 3]
den3=[0 1 2]
sys3=tf(num3, den3)
result2=series(sys3,result1)
num4=[0 0 1]
den4= [0 1 1]
sys4=tf(num4, den4)
result3= feedback(result2,sys4)