Question

The start of an arthmetic sequence is show Below. a) Work out the n term rule for this sequence. b) Work out the 30 term in this sequence. 4,13,22,31

Answer 1

Explanation:

Each term is 9 more than the previous term....the common difference, d = 9

an = a1 + 9(n-1) where a1 is the first term = 4

this reduces to: an = 4 + 9n-9

an = 9n - 5

the 30th term is then a30 = 9(30) - 5 = 265