Algebra 2 Sequences and Series

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

• geometric, a₅ = 625, a_n = 5^n-1

• arithmetic, a₅ = 3125, a_n = 5^n-1

• geometric, a₅ = 3125, a_n = 5ⁿ

• arithmetic, a₅ = 625, a_n = 5ⁿ

Find the sum of the first 6 terms of the sequence:

a = 100 (1/2)^n-1

• 100000

• 1575/8

• 300

• 250

Write the equation for the arithmetic sequence with the following terms:

a₁₄ = -36, a₂₂ = -52

• a = -2n - 8

• a = -8n - 2

• a = -8n - 10

• a = -2n - 10

The number of seats in each row of a concert hall follows the sequence below:

a_n = 16 + 2n

How many seats are in the first 20 rows?

• 56

• 18

• 1480

• 740

Find the equation for the geometric sequence with the following terms:

a₂ = -12, a₅ = -96

• a_n = 2(-6)ⁿ

• a_n = 2(-6)^n-1

• a_n = -6(2)^n-1

• a_n = -6(2)ⁿ

Find the sum of the infinite geometric series, if it exists:

-3 + -3/2 + -3/4 + -3/8...

• -6

• -8

• no sum

• -4

Suppose you are building 10 steps with 8 concrete blocks in the top step and 80 blocks in the last step. If the number of blocks in each step forms an arithmetic sequence, state the values of n, a₁, and a_n. Determine the total number of blocks needed to build these steps using your series formula. Make sure you type out your work.

What is the formula for an arithmetic series?

Complete the sequence: -12, -18, _, -30

Given the sequence: 4, 11, 18, 25, 32, ... Select all values that would appear in the sequence.

• 60

• 68

• 75

• 39

• 81