The first term is given, so
1. The first term is 5.
5 times the common ratio 2 is 10, so
2. The second term is 10.
10 times the common ratio 2 is 20, so
3. The third term is 20.
20 times the common ratio 2 is 40, so
4. The fourth term is 40.
So the first four terms are 5, 10, 20, 40.
Edwin