Question 1205594
 

the arithmetic progression general formula is 

{{{a[n]=a[1]+d(n-1)}}}

given that {{{a[1]=6}}} and {{{d=7}}}


{{{a[n]=6+7(n-1)}}}

now find  the {{{15}}} terms

we know first term, so second term is

{{{n=2}}}
{{{a[2]=6+7(2-1)=13}}}

third term will be

{{{n=3}}}
{{{a[3]=6+7(3-1)=6+14=20}}}

or simply find the next term by adding common difference to previous term

{{{a[4]=27}}}
{{{a[5]=34}}}
{{{a[6]=41}}}
{{{a[7]=48}}}
{{{a[8]=55}}}
{{{a[9]=62}}}
{{{a[10]=69}}}
{{{a[11]=76}}}
{{{a[12]=83}}}
{{{a[13]=90}}}
{{{a[14]=97}}}
{{{a[15]=104}}}

so, first {{{15}}} terms are:
{{{6}}},{{{13}}},{{{20}}},{{{27}}},{{{34}}},{{{41}}},{{{48}}},{{{55}}},{{{62}}},{{{69}}},{{{76}}},{{{83}}},{{{90}}},{{{97}}},{{{104}}}