clc;
close
clear;
s=%s;
b0=1;
b1=2;
b2=3;
b3=4;
a1=5;
a2=6;
a3=7;
tf=syslin('d',((b0*s^3+b1*s^2+b2*s^1+b3)/(s^3+a1*s^2+a2*s+a3)));
ss=tf2ss(tf);
disp(ss)