Answer:
40 terms
Explanation:
the sum to n terms of an arithmetic sequence is
= (a₁ + )
then
(- 4 - 82) = - 1720 ( multiply both sides by 2 to clear the fraction )
- 86n = - 3440 ( divide both sides by - 86 )
n = 40
the series has 40 terms
3.6m questions
4.6m answers
= 
(a₁ + 
) (- 4 - 82) = - 1720 ( multiply both sides by 2 to clear the fraction )