(ITA 2018) Equação polinomial que traz o conceito esquecido de equação recíproca

The polynomial equation is given: (a+c+2) x^3+(b+3c+1) x^2+(c-a)x+(a+b+4)=0 With a, b, c real numbers. Knowing that this equation is a first-kind reciprocal equation and that 1 is a root, then the product abc is equal to: #ita #ime #efomm