Answer:
( 1 , -2 , 4 , -8 , 16 , ... )
( 9 , 3 , 1 , 1/3 , 1/9 , ... )
Step-by-step explanation:
A geometric sequence has a common ratio in consecutive terms,
In sequence,


i.e.
is not a Geometric sequence,
1 , -2 , 3 , -4 , 5 , ...

i.e. 1 , -2 , 3 , -4 , 5 , ... is not a Geometric sequence,
In sequence,
1 , -2 , 4 , -8 , 16 , ...

i.e. 1 , -2 , 4 , -8 , 16 , .... is a Geometric sequence,
In sequence,
0 , 1 , 0 , -1 , 0 , .....

i.e. 0 , 1 , 0 , -1 , 0 , .....is not a Geometric sequence,
In sequence,
9 , 3 , 1 , 1/3 , 1/9 , ...

i.e. 9 , 3 , 1 , 1/3 , 1/9 , ... is a Geometric sequence,
In sequence,
1 , 3 , 5 , 7 , 9 , ...

i.e. 1 , 3 , 5 , 7 , 9 , ... is not a Geometric sequence