I do not even know where to start with this. this proof is for an abstract algebra course.

Suppose f(x) = x^{n }+ a_{1}x^{n-1}+ . . . + a_{1}x + a_{0}where the coefficients a_{0},a_{1}, . . . ,a_{n-1}are integers.

prove: if f(b) = 0 and b is not an integer, then b is irrational.