1. Arithmetic Sequences
Lesson 9-6

2. Vocabulary Sequence – an ordered list of numbers
Term – each number in a sequence
Arithmetic sequence – a sequence in which the common difference is the same
Common difference – the difference between consecutive terms

3. Things to Know
Each term is found by adding the common difference to the previous term.
The common difference is found by subtracting the 2nd term from the 1st term.
Subtract the 3rd term from the 2nd term to make sure the common difference is the same.

4. Example 1 Find the common difference of the arithmetic sequence
4, 11, 18, 25
1/3, 2/3, 1, 4/3
10, 15, 20, 25

5. Your Turn Find the common difference of the arithmetic sequence.
0, 6, 12, 18
400, 500, 600, 700
7.8, 8.8, 9.8, 10.8
5, 5 ¼, 5 ½, 5 ¾

6. Example 2 Write the next three terms of the arithmetic sequence.
6, 8.5, 11, 13.5, ….
14.2, 14.7, 15.2, 15.7, ….

7. Your Turn Write the next three terms of the arithmetic sequence.
45, 60, 75, 90, ….
5 ½, 7, 8 ½, 10, ….

8. Your Turn
Write a sequence to represent the number of blocks in each figure. Is the sequence arithmetic? Explain.

9. Example 3 A golf course charges $38 for one round of golf.
Do the costs in the table show an arithmetic sequence?
A membership to the golf course costs $350 per year. How many rounds of golf must be played for the membership to be the better deal?

10. Your Turn A golf course charges $25 for one round of golf.
Do the costs in the table show an arithmetic sequence?
A membership to the golf course costs $340 per year. How many rounds of golf must be played for the membership to be the better deal?

11. Assignment
Page #2-26 even in Green Textbook