Sequences

Which of the following is not an arithmetic sequence?

• 1/2, 1, 3/2, 2

• 11, 14, 17, 20

• 2, 4, 8, 16

• 5, 2, -1, -4

Identify the common difference of the sequence below:

-2.3, -1.1, 0.1, 1.3,...

• -1.2

• 1.3

• 1.2

• -1.3

Identify the common difference in the sequence shown below:

-9, -13, -18, -23,...

• 4

• -4

Write the explicit formula for the sequence shown below.

3, -3, -9, -15

• a_n=3+6(n-1)

• a_n=3−6(n-1)

• a_n=6−3(n-1)

• a_n=6+3(n-1)

What is the 20^th term of the arithmetic sequence shown below.

7, 4, 1,...

• -49

• 50

• -50

• -51

For the sequence shown below, write the explicit formula then find the 57^th term. What is the 57^th term?

• -266

• -265

• -267

• -260

To find the next term in an arithmetic sequence…

• add the common difference d

• multiply by the common ratio r

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

Is this sequence arithmetic, geometric, or neither?

• arithmetic (common difference d = 5)

• geometric (common ratio r = 5)

• neither (no common difference OR common ratio) neither (no common difference OR common ratio)

Which describes your understanding of arithmetic and geometric sequences?

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How many of these sequences have a common difference of -4?

-19, -15, -11, -7, -3,...

19, 15, 11, 7, 3...

3, 7, 11, 15, 19...

-3, 7, -11, 15, -19,...

• 0

• 1

• 2

• 3