function a17
num1=[0.005];den1=[5 1];num2=[0.005];den2=[4 1];num3=[1250];den3=[1];num4=[0.1];den4=[1];
num5=[1];den5=[0.5 1];
[na,da]=series(num1,den1,num2,den2);
[nb,db]=series(num3,den3,na,da);
[nc,dc]=series(num4,den4,nb,db);

[num,den]=feedback(nc,dc,num5,den5,-1);
printsys(num,den)