Lesson 13.1 Guided Practice A

Given the sequence:

25, 21, 17, 13,...

Write the explicit equation that models the sequence.

• a_n = 25 + (n-1)4

• a_n = 29 + (n-1)(-4)

• a_n = 25 +(n-1)(-4)

• a_n = 29 +(n-1)(4)

Select the explicit rule that represents the sequence.

• a_n = 6 + 5(n - 1)

• a_n = 4 + 6(n - 1)

• a_n = 6 - 4(n - 1)

Write the recursive formula for 6, 17, 28, 39, 50....

• a_n=a_n-1+11
  a₁=6
• a_n=a_n-1-4
  a₁=6
• a_n=a_n-1+9
  a₁=6
• a_n=a_n-1+6
  a₁=6

Write a recursive rule for the sequence 17, 1, -15, -31 . . .

• a_n = a_n-1 + 16
  a₁=17
• a_n = a_n-1 - 17
  a₁=17
• a_n = a_n-1 - 15
  a₁=17
• a_n = a_n-1 - 16
  a₁=17

Create the explicit formula for the sequence:
2, 8, 14, ...
(Hint:  Write your formula and then simplify it.)

• a_n=2+6n
• a_n=-6+6n
• a_n=6n-4
• a_n=4-6n

Identify the common difference.
3, 7, 11, 15, ...

• 6
• 5
• 4
• 2

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

• 8
• 11
• -11
• -8

Given the sequence:
 25, 21, 17, 13,...
Write the explicit equation that models the sequence.  (Hint:  Simplify your equation.)

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

Is the sequence arithmetic: 78, 785, 7855, 78555, ...

• Yes
• No

Find the common difference: 29, 21, 13, 5, ...

• d = -10
• d = -9
• d = -8
• d = -7