Question

Find the 81st term of the arithmetic sequence -2 -8 -14

Answer 1

a₈₁ = - 482

Explanation:

the nth term of an arithmetic sequence is

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

here a₁ = - 2 and d = a₂ - a₁ = - 8 - (- 2) = - 8 + 2 = - 6 , then

a₈₁ = - 2 + (80 × - 6) = - 2 + (- 480) = - 2 - 480 = - 482