What is the recursive formula for this geometric sequence -2, -16,

The sequence is: An = -2*8^(n-1)

Step-by-step explanation:

 geometric sequence is of the form:

An = a*r^(n-1)

where can be any positive integer number.

here the first two numbers are -2 and -16, so we have that:

A1 = a*r^(0) = a = -2

now, we know that our sequence is of the form:

An = -2*r^(n-1)

now, for n= 2 we have that:

A2 = -2*r^(1) = -2*r = -16

r = -16/-2 = 8

now we have determinated our sequence:

An = -2*8^(n-1)

what is the original number? you forgot to add it.

hi there!

first we need to find out how much they are adding to each number to make the next number.

ex: 4 + 4 = 8, 8 + 8 = 16, and so on.

so continuing with 32,

32 + 32 = 64

64 + 64 = 128

128 + 128 = 256

256 + 256 = 512

4, 8, 16, 32, 64, 128, 256, 512

the 8th term of the sequence will be 512

hope this ! ~