Indicate a general rule for the nth term of this sequence.
-6a, -3a, 0a, 3a, 6a. .

an = 3an + 9a
an = -3an - 9a
an = -3an + 9a
an = 3an - 9a

Option D. is the answer.

Step-by-step explanation:

The given sequence is -6a, -3a, 0a, 3a, 6a...........

Since the given sequence is having a common difference d = -3a - (-6a) = -3a + 6a = 3a

Therefore, the given sequence is an arithmetic sequence.

And for an arithmetic sequence general rule or explicit formula is given by

Where a = first term of the sequence

d = common difference

n = number of term which we have to find

Now we put the values from the given sequence

Option D. is the answer.