A1=17 d=3 a18=?

To find the 18th term of an arithmetic sequence (a_n), you can use the formula: \[ a_n = a_1 + (n - 1) \cdot d \] where: - \( a_1 \) is the first term, - \( d \) is the common difference, - \( n \) is the term number. In this case: - \( a_1 = 17 \) - \( d = 3 \) - \( n = 18 \) Now plug these values into the formula: \[ a_{18} = 17 + (18 - 1) \cdot 3 \] \[ a_{18} = 17 + 17 \cdot 3 \] \[ a_{18} = 17 + 51 \] \[ a_{18} = 68 \] So, \( a_{18} = 68 \).