I guess,cma's major is math, all answers are wrong in strict Mat

Be careful, only 5 is a real root, that means the other 3 roots are complex numbers.if we write

f(x)=a(x-2)(x-b) it should be f(f(x))=a^3(x-5)(x-p)(x-q)(x-r).p,q,r are complex numbers.If I'm right,b=3+p,a=2/(6-3p) so,f(0)=(12+4p)/(6-3p).It is easy to get q=h(p),r=g(p).p can take any complex number,if one of q,r is not real number.

I wish 15less say,"Ha,old gingir is hotter".