Question 1109504
{{{system(T[5]=23,T[12]=72)}}}
This goes through seven common difference increments.


{{{23+7*d=72}}}
{{{7d=72-23}}}
{{{7d=49}}}
{{{d=7}}}---------common difference.


A, first term
{{{A+(5-1)*d=23}}}
{{{A+4*7=23}}}
{{{A=23-28}}}
{{{A=-5}}}-------the term, {{{T[1]}}}



General Term, {{{highlight_green(-5+7(n-1))}}};
Go from there.