An arithmetic sequence has this reclusive formula.

D

Step-by-step explanation:

The n th term ( explicit formula ) of an arithmetic sequence is

= a₁ + (n - 1)d

where a₁ is the first term and d the common difference

The recursive formula allows us to find the next term from the previous term by adding d to it

Given

= - 3 ⇒ d = - 3

Hence

= 9 + (n - 1)(- 3) ← explicit formula → D

21

step-by-step explanation:

5x+10 is the correct one

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