Question 1006046
{{{system(0.05n+0.1d=1.5,n-d=3)}}}


{{{system(n+2d=30,n-d=3)}}}


Ready for eliminating n.
{{{3d=27}}}
{{{d=9}}}


{{{n-d=3}}}
{{{n=3+d}}}
{{{n=3+9}}}
{{{n=12}}}