Please help

[mimari]

i am trying to prove this but i couldnt even start. i am new to abstract algebra so i dont know where to start

 

[HallsofIvy]

Since you want to prove "R cannot be a domain". start by reviewing the definition of "domain"!

And since part of what you are given talks about "Abelian groups" I'll bet that the definition of "domain" has something to do with a commutative operation. You will need to use that.