Answer:
aₙ = - 30n + 9
Step-by-step explanation:
You can tell this is an arithmetic sequence, as there is a difference of 30 between each value. Therefore the equation we will use here is aₙ = a₁ + (n - 1)d.
aₙ = a₁ + (n - 1)d
= - 21 + (n - 1) * - 30
= - 21 - 30n + 30
= - 30n + 9
Your solution would be option d. aₙ = - 30n + 9
