x^2 - 2x - 3 < 0 ==> (x -3)(x +1) < 0 ==> -1 < x < 3 x^2 + 4x - 5 < 0 ==> (x +5)(x - 1) < 0 ==> -5 < x < 1 AUB = {x| -5 < x < 3}求采纳
