Equations for Geometric Sequences

Write the explicit formula for the geometric sequence.

• 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

Given the sequence:

125, 25, 5, ....

Write the rule a_n using the geometric sequence formula:

• a_n = (125)(1/5)^(n-1)

• a_n = 625(1/5)^(n-1)

• a_n = 625(5)^(n-1)

• a_n = 125 + 5n

Find the common ratio for the geometric sequence.

• 10
• 1/2
• 2
• 4

Write the explicit formula for the geometric sequence.

• a_n = 10(2)^n-1
• a_n = 2(10)^n-1
• a_n = 10(2)ⁿ
• a_n = 2(10)ⁿ