Arithmetic Sequence Lesson

What are the three formulas that pertain to arithmetic sequences? Write the formulas for each.

An arithmetic sequence is described by the recursive formula shown. What is the explicit formula?

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

• 14
• 68
• 63
• 71

Identify the common difference in the sequence below.

97, 86, 75, 64, ...

• 8

• 11

• -11

• -8

Find the 25th term of the sequence if a₁ = 5 and d = 0.5

• 18
• 17
• 15
• 14

Given the sequence:

25, 21, 17, 13,...

Write the explicit equation that models the sequence. Simplify your answer.

• a_n = 4n + 29

• a_n = - 4n + 25

• a_n = - 4n + 29

• a_n = 4n + 25

The next two terms of the sequence 4,7,10,13 are ....

• 16 and 19
• 15 and 19
• 16 and 18
• 15 and 18

Is the following sequence arithmetic? 17, 9, 1, -7, ...

• Yes

• No

Find a₂₆ in the arithmetic sequence: -15, -35, -55, -75, ...

• -515
• -490
• -535
• 460

Find the sum of the arithmetic series described:

2 + (-2) + (-6) + (-10)..., S₁₀

• -160

• -328

• -320

• -336