Geometric Sequences Explicit

Which of the following is the EXPLICIT formula for geometric sequences?

Predict the 16th term in the following sequence:

5, 10, 20, 40, ...

Which of the formulas below is the EXPLICT formula that would model the sequence below?

Find the next three terms: 4, 12, 36, 108, ...

• 324, 972, 2916

• 972, 2916, 8748

• 405, 1215, 3645

Given the sequence: 125, 25, 5, .... Write the explicit rule:

• t(n) = (125)(5)⁽ⁿ⁾

• t(n) = 125(1/5)^(n-1)

• t(n) = 625(5)⁽ⁿ⁾

• t(n) = 125 + 5n

What is the common ratio for the sequence:
28, 14, 7, 3.5...

• 2

• 1/2

• -14

• -7

Find the common ratio: 4, -16, 64, -256, ...

• r = -4

• r = 2

• r = -2

• r = 4

Write an explicit rule for the general term of the sequence 5, 15, 45, . . . ?

• a_n = a_n-1 x 3

• a_n = 5(3)^n-1

• a_n = 3(5)^n-1

• a_n = 5 + (n-1)3

Find the 11^th term for:  64, -32, 16, -8, …  

• -.0625

• .0625

• -.03125

• .03125

Is the sequence -432, 72, -12, 2,...geometric?

• yes

• no