Your first step would be to unsolve the zeros, which would leave you with x-1, x-1, and x+2. Then arrange the zeros in the position of a factored polynomial, such as (x-1)(x-1)(x+2), and then FOIL the first two terms. You would then end up with, x^2-2x+1(x+2). After this just finish unfactoring the polynomial.
