因为 A∩B = {2,3}所以 | a + 1 | = 2所以 a = 1 或 a = -3当 a = 1 时,2a + 1 = 3 ,a² + 2a = 3 ,在集合B中出现两个相同的元素,所以舍去当 a = -3 时,2a + 1 = -5 ,a² + 2a = 3,a² + 2a - 1 = 2 满...