Question

Find an equation for the nth term of the arithmetic sequence. -15, -6, 3, 12, ...

Answer 1

Answer: $t_{n}=-15+9(n-1)$

Step-by-step explanation:

The formula for finding the nth term of an arithmetic sequence is given as:

$t_{n}=a+(n-1)d$

$a =$ first term = -15

$d =$ common difference = -6 - (-15) = 9

$n =$ number of terms

substituting into the formula , we have :

$t_{n} = -15+(n-1)9$

$t_{n}=-15+9(n-1)$