Detailed solutions please 2 Let R be a commutative ring and
     Detailed solutions please: 2. Let R be a commutative ring and let r, s and r be elements of R with r not equal to OR? Prove that if sr = rt, then either s = t or r is a zero divisor of R.  
  
  Solution
its given that r,s and t are the elements of the commutative ring R
and rs=rt [given]
there the condition that r not = 0
so if r can\'t be zero then
inorder to hold the equation rs=rt as true
we need s = t
or another possiblity could be that the element r is a divisor of R that is
r goes into R some integral number of times.
Hence if sr = rt
we either need
s = t or r be a zero divisor of R

