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, \( a_{18} = 68 \).