Answer:
[tex]a_{16} = 121[/tex].
Step-by-step explanation:
To go from the first term [tex]a_{1}[/tex] of this sequence to the second term [tex]a_{2}[/tex], add [tex]d[/tex] to [tex]a_{1}\![/tex].
To go from the first term [tex]a_{1}[/tex] of this sequence to the third term [tex]a_{3}[/tex], add [tex]2\, d[/tex] to [tex]a_{1}\![/tex].
In general, going from the first term [tex]a_{1}[/tex] of an arithmetic sequence to the [tex]k[/tex]th term, add [tex](k - 1)\, d[/tex] to [tex]a_{1}\![/tex].
Thus, given an arithmetic sequence with [tex]a_{1}[/tex] as the first term and [tex]d[/tex] as the common difference, the [tex]k[/tex]th term of this sequence would be [tex]a_{k} = a_{1} + (k - 1)\, d[/tex].
In this question, [tex]a_{1} = 1[/tex] and [tex]d = 8[/tex] for this arithmetic sequence. The [tex]16[/tex]th term of this sequence would be:
[tex]\begin{aligned}a_{16} &= 1 + (16 - 1) \times 8 \\ &= 1 + 15 \times 8 \\ &= 121\end{aligned}[/tex].
