Answer
$a_{80}=-842$
Work Step by Step
The $n^{th}$ term of an arithmetic sequence can be found using the formula:
$a_n=a_1+(n−1)d$
where
d = common difference
$a_1$ = first term
$a_n$=$n^{th}$ term
The given arithmetic sequence has:
$a_1=106
\\d=-12$
Use the formula above to find the 80th term:
$a_n=a_1+(n−1)(d)
\\a_{80}=106+(80-1)(-12)
\\a_{80}=106+79(-12)
\\a_{80}=106+(-948)
\\a_{80}=-842$
