id	title
1	Art_1
2	Art_2
3	Art_3
4	Art_4

id	location
1	Украина
2	Россия
3	Япония
4	Киев
5	Чернигов

id	loc_id	art_id
1	1	1
2	4	1
3	2	2
4	1	3
5	5	3
6	3	4

SELECT  
  `a`.`id`,
  `a`.`title`,
FROM
  `articles` `a`
  LEFT OUTER JOIN `art2loc`  `b` ON (`a`.`id` = `b`.`art_id`)
  LEFT OUTER JOIN `location` `c` ON (`c`.`id` = `b`.`loc_id`)
WHERE
  `c`.`id` != 1 AND 
  `c`.`id` != 2
GROUP BY
  a.id
ORDER BY
  `a`.`id` DESC
LIMIT 9

SELECT a.*
FROM  `articles` a
WHERE  a.`id` NOT IN (SELECT `art_id` FROM `art2loc` WHERE `loc_id` IN (1,2))