%  define W for each system
close all
clear all
s=tf('s');
W1=4/(s^2+s+2);  W2= 4/(s^2+2*s+3); 
W3=- 4*s/(s^2+s+2); W4=(4*s+1)/(s^2+s+2);

% plot the step response for each system
figure (1)
step(W1,W2,W3,W4)
legend();
hold on
grid on