Formulas for Geometric and Arithmetic Sequences

Arithmetic, geometric, or neither?

4, 9, 14, 19, ...

• Arithmetic

• Geometric

• Neither

Arithmetic, geometric, or neither?

100, 50, 25, 12.5, ...

• Arithmetic

• Geometric

• Neither

Find the common difference:

25, 13, 1, -11, ...

• 12

• -12

• 8

• -8

Find the common ratio:

2, 8, 32, 128, ...

• 1/4

• 4

• 1/6

• 6

Find the next term:

100, 65, 30, -5...

• 20

• -20

• 40

• -40

Create the formula for the geometric sequence:
-4, -16, -64, -256...

• t_n = -4(4)^n-1

• t_n = -4(-4)^n-1

• t_n = 4(4)^n-1

• t_n = 4(4)^n-1

What is the formula for the sequence:

11, 22, 44, 88...

• t_n = 2(11)^n-1

• t_n = 11 + 2(n-1t)

• t_n = 11(2)^n-1

What are the first three terms of the sequence defined by the following equation?
t_n = 7 + (n - 1)5

• 7, 35, 175

• 7, 2, -3

• 12, 17, 22

• 7, 12, 17

What is the 8th term in the sequence below?
3, 9, 27, 81, ...

• 19,683
• 6,561
• 2,187
• 729

What is t₅ in the sequence defined as follows?
t_n = 5 ⋅ 2^(n-1) 

• t₅ = 160

• t₅= 40

• t₅ = 10

• t₅= 80