... (4; 5 ;1) , AC = (3; −6; 4) , Điểm r uuur uuur n = AB, AC = ( 14 ; 13 ; −9) 1. 0 (1. 5 ) mp(ABC): 14 x + 13 y + 9z − 11 0 = 1b uuur uuur BD = (0; 1; 1), AC = (3; −6; 4) (1. 5 ) mp(P): 1c 0 ,5 r ... = 41 + 2a + 12 b + 4c + d = a = 35 + 10 a + 2b + 6c + d = ⇔ b = ( S ) : x + y + z + x + y − z − 68 = 52 + 8a + 12 c + d = c = 1 41 + 10 a + 8c + d = d = −68 1, 0 2a1 (2.0đ) ... BD, AC = (2;3;3) 1. 0 0 ,5 2x + 3y + 3z − 26 = 223 1, 5 (1. 5 ) với a2 + b2 + c2- d > Vì (S) qua điểm A, B, C, D nên ta có 0 ,5 d(D,(ABC)) = 446 (1. 5 ) 1d (S): ( x − 5) 2 + y + ( z − 4)2 = Gọi...