解:$(2)$分三种情况讨论:
$ ①$当$2x - 3 = 1$时,解得$x = 2,$
$ $此时$x + 2 = 4,$$1^4 = 1,$满足题意;
$ ②$当$2x - 3 = -1$时,解得$x = 1,$
$ $此时$x + 2 = 3,$$(-1)^3 = -1\neq 1,$不满足题意;
$ ③$当$x + 2 = 0$时,解得$x = -2,$
$ $此时$2x - 3 = -7,$$(-7)^0 = 1,$满足题意;
综上,$x = 2$或$x = -2$