Using the rational root theorem which states that in a function where is the constant and is the leading coefficent that after you show ALL the factors of and that the only possible rational real roots are all the factors of over all the factors of make sense? so in this case you find the factors of p(i.e. 57) which lucky is is a prime so its factors are 57, 1 and the factors of which once again is aprime so the factors are 3, 1 now take all the p's over q's