设全集I=R,已知集合M={x|(x+3)^2≤0},N={x|x^2+x-6=0}(1)求（CIM)∩N

（1）M = ｛x丨（x + 3）² ≤ 0｝= ｛- 3｝
N = ｛x 丨x ² + x - 6 = 0｝= ｛- 3,2｝
∴ CI M = ｛x 丨x ≠ - 3｝
Ci M ∩ N = ｛2｝
（2）A = Ci M ∩ N = ｛2｝
∵ B ∪ A = A
∴① 当 B 为空集时,则：a - 1 > 5 - a
2 a > 6
a > 3
② 当 B 不为空集时,则：
a - 1 = 5 - a = 2
∴ a = 3
综上,a的取值范围是 a ≥ 3