Question

what is a formula for the nth term of a given sequence
-12,-16,-20...
an = -12(-4)^n
a^n = -12 - 4 (n+1)
an = -8 - 4n
an = -12(-4)^n-1

Answer 1

Answer:

$a_n=-12-4(n-1)$

Step-by-step explanation:

The given sequence is

-12,-16,-20...

The first term of this sequence is $a_1=-12$.

The common difference is

$d=-16--12$

$d=-16+12=-4$

The nth term of this arithmetic sequence is;

$a_n=a_1+d(n-1)$

We substitute the values for the first term and the common difference to obtain;

$a_n=-12-4(n-1)$

Answer 2

Answer:

$a_{n} = -12-4(n-1)$

Step-by-step explanation:

We have given a arithmetic sequence.

-12,-16,-20,...

We have to find formula for a given sequence.

The general formula for nth term of sequence is :

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

In given sequence,

$a_{1} = -12$

d is the common difference between consecutive terms.

d = -16-(-12)  = -16+12

d = -4

Putting given values in formula, we have

$a_{n} = -12-4(n-1)$ which is the answer.