To find the 65th term of the arithmetic sequence that starts at 11 and has a common difference of -5, we can use the formula for the \( n \)-th term of an arithmetic sequence:
\[ a_n = a + (n - 1) \cdot d \]
where:
- \( a \) is the first term,
- \( d \) is the common difference,
- \( n \) is the term number.
For this problem:
- \( a = 11 \)
- \( d = -5 \)
- \( n = 65 \)
Substituting the values into the formula:
\[ a_{65} = 11 + (65 - 1) \cdot (-5) \] \[ a_{65} = 11 + 64 \cdot (-5) \] \[ a_{65} = 11 - 320 \] \[ a_{65} = -309 \]
The 65th term of the sequence is \(-309\).