Which of the following is a geometric sequence?

A is an geometric sequence cause it is multiplying by -3 as it continues. So, as you are seeing below:

3*-3=-9

-9*-3=27

27*-3=-81

And for the other options , some of them were increasing and some were decreasing. They all are arithmetic sequence cause they all include common difference except A. A includes common ratio and that's why it's an geometric sequence.

ur mom

step-by-step explanation:

x = 3 ± √(5+y)