Answer:
the formula is Tn = a + (n-1)d for arithmetic sequence
where Tn is the term, a is the first term, n is the no. of term, d is the difference
a = 8
Using a9=56,
56 = 8 + (9-1)d
48 = 8d
d = 6
thus, Tn = 8 + (n-1)6
when n=24, Tn = 8 + (24-1)(6) = 146
