Question

Write the 1st 3 terms of the sequence whose n^th term is given by 2^n+1.

Answer 1

just plug in 1,2,3 for n:
2^1 + 1 = 2+1 = 3
2^2 + 1 = 4+1 = 5
and so on

Unless you meant that the nth term is 2^(n+1), in which case things will be different, but the method is the same.

Answer 2

and how will they be different

Answer 3

2^5 + 1 = 32 + 1 = 33
2^(5+1) = 2^6 = 64

if that was not clear already, you need to study PEMDAS or similar rules on the order of operations.

Answer 4

Write the 1st 3 terms of the sequence whose ninth term is3n + 8

Answer 5

3n + 8