Question 1177439
for ages d Dylan and n Noelle, the description very literally is:


{{{system(d+n=80,d-10=3(n-10))}}}


Question just asks for d.
Starting approaches to solve can vary.


{{{d=3n-30+10}}}
{{{d=3n-20}}}
{{{d=3(80-d)-20}}}
{{{d=240-3d-20}}}
{{{4d=220}}}
{{{4d=2*11*2*5}}}
{{{d=11*5}}}
{{{highlight(d=55)}}}