The following two sets are given: G = {1, 2, 3; 4, 6, 12} , H = {1, 2, 4, 8, 16}.
Determine the elements of the following two sets: undefined and undefined!

Set S is given undefined. Determine the elements of A i B sets.

$$A=\left\{x|x\in S\wedge \frac{2x}{12-x}\in S\right\}$$ undefined

Determine the elements of the fallowing sets undefined