Question

Which formula can be used to describe the sequence? , −4, −24, −144,...

Answer 1

-4 to -24 you have to multiply 6

-24 x 6 = -144

Formula

a(n) = -4x6(n-1)

Answer 2

`An= -4(6)^(n-1)`

Explanation:

−4, −24, −144,...

There is no common difference

-24/-4= 6

-144/ -24= 6

common ratio = 6

when there is a common ratio then it is an Geometric sequence

`An= a1(r)^(n-1)`

a1 is the first term = -4

r is the common ratio = 6

Formula becomes

`An= -4(6)^(n-1)`