Question

What is the expression for the below sequence (use n) -3,-6,-9,-12

Answer 1

Answer:

$a_{n}$ = - 3n

Step-by-step explanation:

There is a common difference between consecutive terms, that is

- 6 - (- 3) = - 9 - (- 6) = - 12 - (- 9) = - 3

This indicate the sequence is arithmetic with n th term

$a_{n}$ = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = - 3 and d = - 3 , thus

$a_{n}$ = - 3 - 3(n - 1) = - 3 - 3n + 3 = - 3n

The n th term is - 3n