Use the Factor Theorem. A term of the form x - a is a factor of P(x) only when P(a) = 0. So do not choose a factor by appearance; test the value inside the bracket. For this polynomial, the correct listed factors are x - (6), x - (-1). In other words, x - (6) because P(6) = 0, x - (-1) because P(-1) = 0. The other options are not factors because substituting their corresponding values does not make the polynomial equal to zero.