How to find the nth term of a geometric sequence

The nth term of a geometric sequence is given by the formula

first term
common ratio
nth term

1.  Find the 10^th term of the sequence 5, -10, 20, -40, ….​ ​

2. Find the 15th term of the sequence … ​

1.

2.

1. 

2. 

6, 12, 24, 48, …