The image contains a mathematical problem involving sequences and series, with multiple choice questions. Let's analyze and solve the problem based on the provided image content.

Problem Analysis

The given question appears to be related to arithmetic or geometric sequences, specifically asking for the common difference, sum, or properties of sequences.

Question Breakdown

1. Identify the Type of Sequence:

   • We need to determine whether the sequence given is arithmetic or geometric.
   • The sequence provided in the image is: 24, 39, 54, 69, 84.

2. Find the Common Difference (if Arithmetic Sequence):

   • For an arithmetic sequence, the common difference $d$ is found by subtracting any term from the following term.
   • $d = 39 - 24 = 15$
   • $d = 54 - 39 = 15$
   • $d = 69 - 54 = 15$
   • $d = 84 - 69 = 15$
   • Since the difference is constant, this is an arithmetic sequence with $d = 15$.

3. Sum of the Sequence:

   • The sum of the first $n$ terms of an arithmetic sequence is given by: $S_n = \frac{n}{2} \times (2a + (n - 1) \times d)$
   • Where $a$ is the first term and $d$ is the common difference.
   • However, in this specific question, it seems that they are asking about the properties or patterns within the sequence rather than its sum.

4. Understanding the Options:

   • The image also shows multiple-choice answers. We would need to interpret what each option represents based on the context, such as the common difference, sum, or a property of the sequence.

Solution

Based on the understanding of the problem:

• Option A is likely referring to finding a particular property (e.g., common difference, specific term, or sum of terms).
• Option B might involve deriving a general formula.
• Option C could focus on identifying a pattern or sum.
• Option D might involve extending the sequence or summing all terms.

Given the direct computation and properties discussed:

1. The common difference $d = 15$.
2. Formula for the nth term:
   • $a_n = a_1 + (n-1) \times d = 24 + (n-1) \times 15 = 15n + 9$.
3. Sum of the first n terms if required:
   • Using $S_n = \frac{n}{2} \times (2a + (n - 1) \times d)$.

To solve the specific choices given, you'll need to match this analysis with the options provided. If you can share more specific instructions on which particular question within the image to address, I can provide a more detailed solution.

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Would you like more detailed calculations or explanations on any part of this solution? Here are some follow-up questions that might help expand your understanding:

1. What is the sum of the first 10 terms of this arithmetic sequence?
2. How would the formula for the nth term change if the sequence were geometric instead?
3. How can you determine the 50th term in this sequence?
4. What properties distinguish an arithmetic sequence from a geometric sequence?
5. How does the sum formula for an arithmetic sequence change if the sequence starts from a term other than the first?

Tip: When solving problems involving sequences, always start by identifying the type of sequence (arithmetic, geometric, etc.) to apply the appropriate formulas.