Question

“Identify the CORRECT formula based on the sequence” do not answer on some bs .

Answer 1

see explanation

Explanation:

there is a common ratio between consecutive terms , that is

21 ÷ 7 = 63 ÷ 21 = 3

this indicates the sequence is geometric with explicit formula

`a_(n)` = a₁
`r^(n-1)`

where a₁ is the first term and r the common ration

here a₁ = 7 and r = 3 , then

`a_(n)` = 7 .
`3^(n-1)` ← explicit formula

the recursive formula allows a term to be found by multiplying the previous term by r , then

`a_(n)` = 7 .
`a_(n-1)` ← recursive formula