Algebra-1

Question Analysis
This question tests the student's ability to identify and use the common ratio in a geometric sequence to find the explicit formula.

Key Concept Explanation
In a geometric sequence, each term after the first is found by multiplying the previous term by a constant called the common ratio (). The explicit formula for the -th term is given by (), where is the first term and is the common ratio.

Step-by-step Solution
1. Identify the first term :