O.
the sum of the first k terms of a sequence is 3k^2 + k.
(a) find the 6th term of the sequence.
(b) determine whether the sequence is an arithmetic sequence.

(a) 34.

(b) Yes.

Step-by-step explanation:

The first term is 3(1)^2 + 1 = 4 ( where k = 1).

The sum of 2 terms =  3(2)^2 + 2 = 14.

The sum of 3 terms = 3(3)^2 + 3 = 30.

The sum of 4 terms = 3(4)^2 + 4 = 52.

So the first 4 terms are 4, 10, 16 and 22 .     - increasing by 6.

The common difference is 6 so it is an arithmetic sequence.

The 6th term = a1 + d(n - 1)

= 4 + 6(6-1)

= 34.

The answer is C, 7.5.

This is because you know that these are the same objects, since it’s asking to find the scale factor. You are able to correlate AB to EF, and that shows a scale UP of 1.5, from 2 to 3. With this scale factor of 1.5, we know that EH will be 1.5 times bigger than AD. So 1.5 x 5 is equal to 7.5.