Rules for Arithmetic and Geometric Sequences help?

Question

For each problem show all work leading to your answer and write the answer in simplest form. 
Use Rules to Determine Sequences 
1. Use the rule t^n=-3n+55  to find the first five terms in the arithmetic sequence.

2.Use the rule  t^n= 5(2)^n-1 to find the first five terms in the geometric sequence​

 

Answer 1

(1)

 term of arithmetic sequence is .

Find the first five terms in the arithmetic sequence.

Substitute  in   term to find the first five terms.

.

First five terms of the arithmetic sequence are 52, 49, 46, 43, 40.

Answer 2

(2)

term of geometric sequence​ is .

Find the first five terms in the geometric sequence​.

Substitute in  term to find the first five terms.

First five terms of the geometric sequence​ are 5, 10, 20, 40, 80.