ANSWER
a9 = 64
EXPLANATION
The formula to find the nth term of an arithmetic sequence is,
[tex]a_n=a_1+d(n-1)[/tex]Where a1 is the first term of the sequence and d is the common difference.
In this problem, the first term is a1 = 8 and the common difference is d = 7, so the formula for the nth term is,
[tex]a_n=8+7(n-1)[/tex]If we want to find the 9th term, we have to replace n by 9 in the equation above,
[tex]a_9=8+7\cdot(9-1)[/tex][tex]a_9=8+7\cdot8=8+56=64[/tex]Hence, the 9th term of the sequence is 64.
