Question 946811
The common difference is {{{7/2-5=7/2-10/2=-3/2}}}.
The first term is {{{5}}}.
So,
{{{a[n]=5-(3/2)(n-1)}}}
When {{{a[n]=-19}}}, then,
{{{5-(3/2)(n-1)=-19}}}
{{{-(3/2)(n-1)=-24}}}
{{{n-1=16}}}
{{{n=17}}}
The 17th term.