Question 1205669
ARITHMETIC sequence {{{A+(n-1)d}}} general term
n is index
d is common difference between terms
A is first term



(fixed)


Description gives the equation system  {{{system(A+10d=57,and,A+(A+3d)=29)}}}.


{{{system(A+10d=57,2A+3d=29)}}}


{{{system(A=57-10d,2A+3d=29)}}}


{{{2(57-10d)+3d=29}}}


{{{114-20d+3d=29}}}

{{{114-29=17d}}}

{{{d=(114-29)/17}}}

{{{d=5}}}

-

{{{A=57-10*5}}}

{{{A=7}}}

-

general term, {{{highlight(7+5(n-1))}}};
do what you need from that.