So, the coefficients are not the same, but they are similar.
%[1 -0.6667 -1.3333] is equal to [3 -2 4]/3.
This is because, poly() calculates equation in the form of x^2+b*x+c (a=1) instead of the generalised form a*x^2+b*x+c (i.e. the function is written in such a way).
If you want your solution to be in the generalised form, what you can do is multiply the equation with the first member of original equation.
p=[3 -2 4];
r=roots(p);
q=p(1)*poly(r);
