Find the First and Third Partial Sums, S1 and S3 $$a _ { n } = 3 ^ { n } - 6$$

Multiple Choice

Find the first and third partial sums, s1 and s3, for the sequence
- $$a _ { n } = 3 ^ { n } - 6$$

A) -3, 33
B) -3, 9
C) -3, 21
D) -3, 0