Arithmetic Sequences and Partial Sums

Given the sequence: 25, 21, 17, 13,... Write the explicit equation that models the sequence.

• a_n = 4n + 29

• a_n = - 4n + 25

• a_n = - 4n + 29

• a_n = 4n + 25

Find the common difference:  a₂ = 6 and a₆ = -14

• -1

• -5

• -2

• 2

Which recursive formula best describes the following sequence:
3, 8, 13, 18, 23...

• a_n = (3)^n-1 ; a₁ =5

• a_n = (5)^n-1 ; a₁ =3

• a_n = a_n-1+3 ; a₁ =5

• a_n = a_n-1+5 ; a₁ =3

Find S_n for the given series:
a₁=22
d=-8
n=21

• 1911

• -1449

• -2436

• -1218

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

Is this sequence arithmetic, geometric, or neither?

• arithmetic (common difference d = 5)

• geometric (common ratio r = 5)

• neither

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

• 14

• 68

• 63

• 71

Find the 32nd term of this sequence.
34, 37, 40, 43, ...

• 32

• 64

• 127

• 356

Evaluate the Arithmetic Series

• 105

• 210

• 100

• 420

Is this summation finite or infinite?

• Finite, because there are only 6 terms to add up.

• Infinite, because there are an infinite number of terms to add up.

The number of seats in each row of a concert hall follows the sequence below: a_n = 16 + 2n Which row has 38 seats?

• 16

• 92

• 12

• 15