Question 1044597
Either there is a typo, and the wording of the problem is not exactly as posted,
or this could be called a trick question.
{{{n}}}= the numerator
{{{d=n+K}}}= the denominator
{{{2*d=2(n+K)}}}= the denominator, doubled
 
The original number is {{{n/d}}} .
The number with the denominator doubled (just the denominator) is {{{n/2d}}} .
For both of those numbers to be equal, the only solution is {{{n=0}}} .
That would make the original number {{{0/K=0}}} ,
and the number with the denominator doubled would be {{{0/2K=0}}}.