Question 316802
For the largest value of a fraction, choose the maximum value for the numerator divided by the minimum value for the denominator.
If the denominator was zero, the value of the fraction would be infinite. 
In that case,
{{{m-2n=0}}}
{{{m=2n}}}
Since the maximum value m can take on is 2009. 
Let's use the closest value to {{{m/2}}} which would be {{{n=1004}}}.
{{{m-2n=1}}}
{{{2m+n=5022}}}
{{{(2m+n)/(m-2n)=5022}}} when {{{m=2009}}} and {{{n=1004}}}