Review Sequences and Series

What is the explicit formula for the sequence?

What is a₅ in the sequence defined as follows?
a_n = 5 ⋅ 2^(n-1) 

• a₅ = 160

• a₅ = 40

• a₅ = 10

• a₅ = 80

Identify the common difference.
97, 86, 75, 64, ...

• 8

• 11

• -11

• -8

-21, -16, -11, -6, ...

Is this sequence arithmetic, geometric, or neither?

• arithmetic (common difference d = 5)

• geometric (common ratio r = 5)

• neither

Describe the sequence, find the 5th term, and write the rule

-8, -6, -4, -2...

• geometric, a₅ = 2, a_n = 2n - 10

• geometric, a₅ = 0, a_n = -10n + 2

• arithmetic, a₅ = 2, a_n = -10n + 2

• arithmetic, a₅ = 0, a_n = 2n - 10

The next term of the sequence 2,4,8,16 is

• 64

• 32

• 108

• 20

Is the sequence 2, 4, 12, 48,... geometric?

• yes

• no

What is the common ratio for the sequence:
28, 14, 7, 3.5...

• 2

• 1/2

• -14

• -7

Find the 22nd term of the following sequence:
5, 8, 11, ...

• 14

• 68

• 63

• 71

Evaluate the series.

• 36

• 85

• 35

• 86