x²-2x-3＜0(x-3)(x+1)＜0x-3＜x+1所以，x-3＜0且x+1＞0即-1＜x＜3
不等式可改写为(x－3)(x＋1)＜0 解集是-1＜x＜3
x²-2x-3＜0(x-3)(x+1)＜0∴x＜-1或x＞3
