A1 or just a as it is in the equations is just the initial term of the sequence. In this case a1=1
r is the common ratio which is that constant ratio found by dividing any term by the term preceding it...
In this case r=3/1=9/3=27/9=etc=3
So a1=1 and r=3, C. is your answer.
That would be.... placoderm fish
It will be all these
1+3
2+2
4+0
If I knew the answer I would helped u b,

ut I'm only in 7th grade but I will try
Answer:
Step-by-step explanation:
they had at least 989 people at the amusement park