prove if we want that the sum of some fractions be and the denominators of one of them is then another denominators should divisible by or should be divisible to another denominators.
It seems to be easy I tried to prove it.I first tried some cases.
Here we can see that is divisible by . Also here is divisible by .But I want to prove one of the denominators but here two of them is possible.After trying a lot I cannot found any proofs.Any hints?
update1: the numerator should be prime