To identify the explicit formula for the sequence \( 12, 6, 0, -6, \ldots \), we first observe the pattern in the sequence.
The first term \( A_1 \) is 12. The second term \( A_2 \) is 6. The third term \( A_3 \) is 0. The fourth term \( A_4 \) is -6.
Next, we can notice that the sequence is decreasing by 6 each time:
- \( 12 - 6 = 6 \)
- \( 6 - 6 = 0 \)
- \( 0 - 6 = -6 \)
This indicates that the sequence is an arithmetic sequence where the first term \( a = 12 \) and the common difference \( d = -6 \).
The general formula for an arithmetic sequence is given by: \[ A_n = a + (n - 1)d \] Substituting the values we have:
- \( a = 12 \)
- \( d = -6 \) So, the formula becomes: \[ A_n = 12 + (n - 1)(-6) \] This matches the first response you have provided.
Therefore, the correct explicit formula that represents the sequence is: \[ A_n = 12 + (n - 1)(-6) \]