1. The [3] in (1,2) has only 3 blanks linked to it, thus (1,1), (1,3) and (3,2) must contain an (X).​

2. The [1] in (2,2) has an (X) linked to it in (3,2), and thus (2,1) and (2,3) must contain a (-).

3. The [2] in (3,1) has 2 (X)'s linked to it in (1,1) and (3,2), and thus (3,3) must contain a (-).

answer: