67. For any real number, 222 1 13 23x axx x+ + ≤− +is always true, then the range of real numbers a
問題詳情
67. For any real number, 222 1 13 23x axx x+ + ≤− +is always true, then the range of real numbers a is (A) − 3 ≤ a ≤ 1 (B) −1 ≤ a ≤ 3 (C) − 2 ≤ a ≤ 1 (D) − 1 ≤ a ≤ 2