To find the 10th term of an arithmetic sequence, follow these steps:### Given Arithmetic Sequence:\[ 12, 13, 18, 21, \ldots \]1. **Identify the first term \(a\) and the common difference \(d\):** - The first term \(a\) is \(12\). - To find the common difference \(d\), subtract the first term from the second term: \[ d = 13 - 12 = 1 \] - However, if we check the second and third terms: \[ d = 18 - 13 = 5 \] - It seems there is an inconsistency in the given terms. To confirm the correct pattern, let’s use \(d = 5\) (the difference between the second and third terms).2. **Use the formula for the \(n\)-th term of an arithmetic sequence:** \[ a_n = a + (n - 1) \cdot d \] Where: - \(a = 12\) (first term) - \(d = 5\) (common difference) - \(n = 10\) (the term number we are finding)3. **Calculate the 10th term:** \[ a_{10} = 12 + (10 - 1) \cdot 5 \] \[ a_{10} = 12 + 9 \cdot 5 \] \[ a_{10} = 12 + 45 \] \[ a_{10} = 57 \]**Conclusion:**The 10th term of the arithmetic sequence is \(57\).