Question

Which of the following is the algebraic expression that best describes the sequence 3 , 9 , 27 , 81 , 243

A) 3x
B) 3x + 3
C) x + 3
D) 3^x

Answer 1

You are multiplying by 3 each time. This sequence is geometric.

9 = 3*3 = 3^2

27 = 3*9 = 3*3*3 = 3^3

81 = 3*27 = 3*3*3*3 = 3^4

and so on.

The general rule is 3^x which is choice D