... (SAD)) = d(H, (SAD)) = HL = 21 7a. Câu V: 1 (1 ) 1 (1 ) 1 (1 ) 1 1 1 abcTabc = 1 1 1 1 1 1 1 1 1 abcabc Ta có: 1 1 1 9 1 1 1 1 1 1a b c a b c; 0 1 1 1 6abc (Bunhia) 96626T. ... BĐT Cô–si ta có: 3 3 3 1 1 3 1 1 3 1 1 3;; (1 ) (1 ) 8 8 4 (1 ) (1 ) 8 8 4 (1 ) (1 ) 8 8 4a b c a b c a b c a b c b c c a a b 3 3 333 3 3 3 (1 ) (1 ) (1 ) (1 ) (1 ) (1 ) 2 4 2 4 4a b c a ... = (c2 + d2)n Cõu VI.b: 1) Tỡm c C (1; 1) 1 , C2( 2; 10 ). + Vi C 1 (1; 1) (C): 11 11 16 03 3 322x y x y + Vi C2( 2; 10 ) (C): 91 91 416 03 3 322x y x y 2) Gi...