With reference to Exercise 12, describe the ring Q(3Z, {6ⁿ |n ∈ Z+}) by describing a subring of R to which it is isomorphic. 

Data from Exercise 12

Let R be a nonzero commutative ring, and let T be a nonempty subset of R closed under multiplication and containing neither 0 nor divisors of 0. Starting with R x T and otherwise exactly following the construction in this section, we can show that the ring R can be enlarged to a partial ring of quotients Q(R, T). Think about this for 15 minutes or so; look back over the construction and see why things still work.