Geometric Sequences and Series

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

Find the common ratio for the following geometric sequence:

7, -7, 7, -7, ...

• 1

• -1

• 7

• -7

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

• 36, -108, 324
• -324, -972, -2916
• 324, -972, 2916
• -108, 324, -972

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

Write the explicit formula for the following geometric sequence:

10, 20, 40, 80, ...

• a_n = 10(2)^n-1

• a_n = 2(10)^n-1

• a_n = 10(2)ⁿ

• a_n = 2(10)ⁿ

Write the explicit rule for the following geometric sequence:

2, -12, 72, ...

• a_n = 72(-6)^n-1

• a_n = 2(-6)^n-1

• a_n = 2(6)^n-1

• a_n = 72(-6)^n-1

Write the explicit formula for the following geometric sequence:

3, -12, 48, -192, ...

• a_n = 4(3)^n-1

• a_n = 3(4)^n-1

• a_n = -4(3)^n-1

• a_n = 3(-4)^n-1

Find the first four terms of the sequence given the rule:
a_n = 4(5)^n-1

• 20, 100, 500, 2500
• 5, 20, 80, 320
• 4, 20, 100, 500
• 4, 9, 14, 19

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...