To identify the explicit formula for the sequence 12, 6, 0, -6, ..., we first observe the pattern in the sequence.
- The first term \( A(1) = 12 \)
- The second term \( A(2) = 6 \)
- The third term \( A(3) = 0 \)
- The fourth term \( A(4) = -6 \)
The difference between consecutive terms is \( -6 \):
- \( 6 - 12 = -6 \)
- \( 0 - 6 = -6 \)
- \( -6 - 0 = -6 \)
This indicates that the sequence decreases by 6 with each step.
The general form of a linear sequence can be written as: \[ A(n) = A(1) + (n - 1)d \] where \( A(1) \) is the first term and \( d \) is the common difference.
Here:
- \( A(1) = 12 \)
- \( d = -6 \)
Substituting the values in, we get: \[ A(n) = 12 + (n - 1)(-6) \]
This simplifies to: \[ A(n) = 12 - 6(n - 1) \] \[ A(n) = 12 - 6n + 6 \] \[ A(n) = 18 - 6n \]
From the options given, we notice the closest match is:
- \( A_n = 12 + (n - 1)(-6) \)
Thus, the explicit formula that represents the sequence is: \[ \boxed{A_n = 12 + (n - 1)(-6)} \]