Sequences and Series

Which recursive formula best describes the sequence
2, -6, 18, - 54... 

• a_n=a_n-1* -4, a₁ = 2
• a_n=a_n-1* - 8, a₁ =2
• a_n=a_n-1* 2, a₁ = -3
• a_n=a_n-1* -3, a₁ =2

Given the sequence:
 25, 21, 17, 13,...
Write the explicit equation that models the sequence.

• a_n = 4n + 29
• a_n = -4n + 25
• a_n = -4n + 29
• a_n = 4n + 25

What is a rule where one or more previous terms of a sequence are used to generate the next term?

• explicit formula
• recursive formula
• sequence
• series

Identify the common difference.
97, 86, 75, 64, ...

• 8
• 11
• -11
• -8

What kind of formula is a_n = 5n + 3?

• Arithmetic Recursive
• Arithmetic Explicit
• Geometric Recursive
• Geometric Explicit

Find the sum, if possible

• -4/3
• 4/15
• 1
• not possible

What is the twelfth term in the sequence 3, -6, 12, . . . ?

• -2,048
• 6,144
• -6,144
• -531,441

Find the rule (explicit formula) for the geometric sequence. 
-3,-18,-108,-648,...

• a_n = 3(-6)^n-1
• a_n = -3(6)^n-1
• a_n = -2(6)^n-1
• a_n = 2(-6)^n-1

Which sequence is represented by the equation 2(7)^n-1 ?

• 7, 14, 28, 56...
• 2, 14, 98, 686...
• 2, 9, 16, 23...
• 7,9,11,13...

Find the values

• 6, 10, 14, 18
• 1, 5, 9, 13
• 0, 4, 8, 12
• 2, 6, 10, 14