Which sequence is represented by the expression 2(7)^n-1

Question

a) 7, 14, 28, 56...

b) 2, 14, 98, 686...

c) 2, 9, 16, 23...

d) 7, 9, 11, 13...

Answer 1

n represents the order of numbers in the sequence.

n₁, n_2, n_3,...n_k

For this type of problem, plug in 1, 2, 3,...to find out each number in the sequence.

For the first number:

2(7)^[1]-1

2(7)⁰

2(1)

2

Answer 2

You are given the expression for the sequence to be 2(7)^(n-1). So now to find the values of the sequence you can start plugging in values for n.

n=1: 2(7)^(1-1) = 2(7)^0 = 2*1 = 2

n=2: 2(7)^(2-1) = 2(7)^1 = 2*7 = 14

n=3: 2(7)^(3-1) = 2(7)^2 = 2*49 = 98

and so on.

Hope this helps!