Question

What are the possible rational zeros of f(x) = x4 + 2x3 – 3x2 – 4x + 18 ?

± 1, ± 2, ± 3, ± 4, ± 5, ± 6, ± 7, ± 8, ± 9, ± 10, ± 11, ± 12, ± 13, ± 14, ± 15, ± 16, ± 17, ±18

± 1, ± 2, ± 3, ± 6, ± 9, ± 18

1, 2, 3, 6, 9, 18

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18

please help

Answer 1

Any possible zero of the polynomial has to be a (positive or negative) factor of the constant term (18).
Any of the choice that contains a number which does not divide 18 is not valid.