To find the 83rd term of the arithmetic sequence given by \( a_n \), we first need to determine the first term \( a_1 \) and the common difference \( d \).
From the sequence:
- The first term \( a_1 = -22 \)
- The second term is \( -18 \)
To find the common difference \( d \): \[ d = a_2 - a_1 = -18 - (-22) = -18 + 22 = 4 \]
Now, we can use the formula for the \( n \)-th term of an arithmetic sequence: \[ a_n = a_1 + (n - 1)d \]
Substituting the values we have:
- \( a_1 = -22 \)
- \( d = 4 \)
- \( n = 83 \)
Now, calculate \( a_{83} \): \[ a_{83} = -22 + (83 - 1) \cdot 4 \] \[ = -22 + 82 \cdot 4 \] \[ = -22 + 328 \] \[ = 306 \]
Thus, the 83rd term of the arithmetic sequence is \( \boxed{306} \).