The ring {0, 2, 4, 6, 8} under addition and multiplication moduloo 10 has a unity. find it.

Let R={0,2,4,6,8}, +, x modulo 10 By Theorem if R has a unity it is unique. ... 6x0=0, 6x2=12=2 mod 10, 6x4=24=4 mod 10, 6x6=36=6 mod 10, 6x8=48=8 mod 10 Therefore, 6xa=a mod 10 an...