Question

What is the 24th term of the arithmetic sequence where a1 = 8 and a9 = 56?

Answer 1

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

Answer 2

Since this is an arithmetic sequence it would just be 8 x 24 which is 192