17. Given that (I, 1.) in an ideal of the ring (R, +,), show that a) whenever (R, 1,) is commutative with identity, then so is the quotiont ring (R/1,+,), b) the ring (R/1,+,) may have divisors of...

Extracted text: 17. Given that (I, 1.) in an ideal of the ring (R, +,), show that a) whenever (R, 1,) is commutative with identity, then so is the quotiont ring (R/1,+,), b) the ring (R/1,+,) may have divisors of zero, even though (R, +,) docs not have any, c) if (R,+,) is a principal ideal ring, then so is the quotient ring (R/I, +,).