What is the sequence?

243, 81, 27, 9, 3, 1

9514 1404 393

  an = 243·(1/3)^(n-1) = 3^(6-n)

Step-by-step explanation:

This geometric sequence has a first term of a1=243 and a common ratio of r = 81/243 = 1/3. The general term for it is ...

  an = a1·r^(n-1)

  an = 243·(1/3)^(n-1)

Making use of the rules of exponents, this can be simplified to ...

  an = 3^5·(3^-1)^(n-1) = 3^(5-n+1)

  an = 3^(6-n)

9 x 8 divided by (5-3)=36