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3.8.1: Arithmetic Sequences

Just as Julian finished his homework, he went to feed his fish and accidentally dropped his homework in the fish tank. He was working on patterns of numbers and the last number in four of the patterns was washed away by the water in the fish tank. Julian needs help recreating his patterns. Describe the pattern and determine the next number in the list.

1. 1, 3, 5, 7, …

2. 13, 18, 23, 28, …

3. 7, 4, 1, –2, –5, …

4. –22, –15, –8, –1, … 2

3.8.1: Arithmetic Sequences

1. 1, 3, 5, 7, …

• In this list of numbers, each number is 2 more than the previous number. Add 2 to 7 to get the next number in the list. The next number in the list is 9.

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3.8.1: Arithmetic Sequences

2. 13, 18, 23, 28, …

• In this list of numbers, each number is 5 more than the previous number. Add 5 to 28 to get the next number in the list. The next number in the list is 33.

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3.8.1: Arithmetic Sequences

3. 7, 4, 1, –2, –5, …

• In this list of numbers, each number is 3 less than the previous number. Subtract 3 from –5 to get the next number in the list. The next number in the list is –8.

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3.8.1: Arithmetic Sequences

4. –22, –15, –8, –1, …

• In this list of numbers, each number is 7 more than the previous number. Add 7 to –1 to get the next number in the list. The next number in the list is 6.

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3.8.1: Arithmetic Sequences