Question 1091620
{{{system(2m+n=7,-m+n=-2)}}}


Easy to ELIMINATE n.
{{{2m+n-(-m+n)=7-(-2)}}}
{{{2m+n+m-n=9}}}
{{{3m=9}}}
{{{m=3}}}



{{{n=m-2}}}
{{{n=3-2}}}
{{{n=1}}}



RESULT:  {{{system(m=3,n=1)}}}