s=tf('s');
num=1;
den=[1 5 6];
G=tf(num, den);
den1=conv([1,2], [1,3]); %den 1 = den
G1=tf(num,den1);
G2=1/((s+2)*(s+3));
step(G);
%[y,t] = step(G);
[numG, denG]=tfdata(G);
G.den{1};
roots(G.den{1});
yy=(1/6)+(1/2)*exp(-2*t)+(-2/3)*exp(-3*t);
plot(t, [y yy]);