Which polynomial equations have -i as one of their roots? x3 - 6 x2 - 16 x + 96 = 0 x3 - x2 + x - 1 = 0 x3 - 2 x2 + x - 2 = 0 x3 + 3 x2 + x + 3 = 0 x3 + 5 x2 - 20 = 0