If you make a multiplication table for the given ring, you can see that 6*x = x for all x in R, so 6 is the unity.
The multiplication table is:
2 | 4 | 6 | 8
2 | 4 | 8 | 2 | 6
4 | 8 | 6 | 4 | 2
6 | 2 | 4 | 6 | 8
8 | 6 | 2 | 8 | 4
--Podarcze 16:39, 10 March 2009 (UTC)
