How to factor symbolic equations

I'm trying to factor a symbolic equation but I keep getting errors.

the code is basically this

syms c
SE1=c^2-2*c+1;
SQ1=SE1==25;
factor(SQ1)

and the error I get is

Error using mupadengine/feval_internal
Invalid argument.

Error in sym/factor (line 92)
l = feval_internal(symengine, 'factor', xsym, opt);

I can find nothing online about this issue so either I'm missing something obvious or I'm not searching with the right words.

Answer 1

[Chunru]

syms c
SE1=c^2-2*c+1;
SQ1=SE1==25;

% you can factor a symbolic function but not an equation
factor(SE1)

ans = 

factor(SE1-25)

ans =