In an arithmetic sequence, the nth term can be found using the formula:
\[ a_n = a_1 + (n - 1) \cdot d \]
where:
- \(a_n\) is the nth term,
- \(a_1\) is the first term,
- \(d\) is the common difference,
- \(n\) is the term number.
In this sequence:
- The first term \(a_1 = -4\).
- The common difference \(d\) can be calculated as follows: \[ d = 0 - (-4) = 4 \] (This is consistent since \(4 - 0 = 4\), \(8 - 4 = 4\), etc.)
Now we can calculate the 9th term using the formula:
\[ a_9 = a_1 + (9 - 1) \cdot d \] \[ a_9 = -4 + 8 \cdot 4 \] \[ a_9 = -4 + 32 \] \[ a_9 = 28 \]
Thus, the 9th term \(a_9\) is \(28\).
The answer is B. \(a_9 = 28\).
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