How do I fix this error?

clear all
clc
syms s
K=1;
Gnum=(50/3)*K;
Gden=sym2poly((s+5)*(s+(10/3))*(s+2));
G=tf(Gnum,Gden);
H=20/(s+20);
figure
rlocus(G*H*K);
T=feedback(G*K,H);
figure
step(T)
figure
rlocus(T)

Error using * (line 80)

Invalid operand. Variables of type "sym" cannot be combined with other models.

Error in rootlocusKanalysis (line 16)

rlocus(G*H*K);

Answer 1

[Walter Roberson]

You can never create a tf directly from something symbolic.

s = tf('s');
K=1;
Gnum=(50/3)*K;
Gden=(s+5)*(s+(10/3))*(s+2);
G=tf(Gnum,Gden);
H=20/(s+20);
figure
rlocus(G*H*K);

T=feedback(G*K,H);
figure
step(T)

figure
rlocus(T)

[Isyraf Izuddin]

https://www.youtube.com/watch?v=A_kdC7m8Prs

I follow the coding from this YouTube video there no error when use his equation but when i try using our group equation there is error.

I am a student Please help me

and I also attach my assignment question

[Walter Roberson]

In that video, at no point does the speaker use a symbolic H.

clear all
clc
syms s
K=1;
Gnum=(50/3)*K;
Gden=sym2poly((s+5)*(s+(10/3))*(s+2));
G=tf(Gnum,Gden);
Hnum = 20;
Hden = sym2poly(s+20);
H=tf(Hnum,Hden)

H =
 
    20
  ------
  s + 20
 
Continuous-time transfer function.

figure
rlocus(G*H*K);

T=feedback(G*K,H);
figure
step(T)

figure
rlocus(T)

[Isyraf Izuddin]

Thank you very much... very appriciate your help... may Allah bless you...