The function  f(x)= x^{2}(x+2) has a 1-2 distribution of zeros while the function  g(x) = x^{2}(x+2) has a 2-1 distribution of zeros. For what values of "a" will  f(x) = x^{2}(x+2) +a have a 1-1-1 distribution of zeros? For what values of "b" will  g(x)= x^{2}(x+2) - b have a 1-1-1 distribution of zeros?


I'm not understanding this? any knowledge about distribution of zeros would be helpful.