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

and how will they be different

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.

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

3n + 8

To find the first three terms of the sequence whose n-th term is given by 2^n+1, we can substitute the values of n starting from 1 and find the corresponding terms.

The n-th term of the sequence is given by 2^n+1. Let's substitute the values of n and find the first three terms:

For n = 1:
2^1+1 = 2^2 = 4

So, the first term of the sequence is 4.

For n = 2:
2^2+1 = 2^3 = 8

So, the second term of the sequence is 8.

For n = 3:
2^3+1 = 2^4 = 16

So, the third term of the sequence is 16.

Hence, the first three terms of the sequence are 4, 8, and 16.