... 2; -3 ), B(0; 3; 7), C (12; 5; 0) b) A(0; 13; 21), B(11; -2 3; 17), C (1; 0;19) c) A (3; -4 ; 7), B (-5 ; 3; -2 ), C (1; 2; -3 ) d) A(4; 2; 3) , B (-2 ;1; -1 ), C (3; 8; 7) e) A (3; -1 ; 2), B(1; 2; -1 ), C (-1 ;1; ... B (-1 ;1; 0), C (3; 1; -1 ) b) A ( -3 ; 2; 4), B(0; 0; 7), C (-5 ; 3; 3) A (3; -1 ; 2), B(1; 2; -1 ), C (-1 ;1; -3 ) d) A(0; 13; 21), B(11; -2 3; 17), C (1; 0;19) A(1; 0; 2), B (-2 ;1;1), C (1; -3 ; -2 ) f) A(1; -2 ; ... c = (3; -2 ; 4) f) a = (5; 4; -8 ), b = (-2 ; 3; 0), c = (1; 7; -7 ) r r r r r r h) a = (2; -4 ; 3) , b = (-1 ; 3; -2 ), c = (3; -2 ;1) g) a = (2; -4 ; 3) , b = (1; 2; -2 ), c = (3; -2 ;1) r r r Bài 13 Tìm...