Which function can be used to describe the sequence? -2/3, -4, -24

Answer #3 is correct

6 is the common ratio (r)
first term is -2/3 (a)
the general equation is f(x)=a(r)^x-1
so plug in the number
f(x)=-2/3(6)^x-1

Then why is the question on here if you know the answer