Question

Which of the following is the formula for the geometric sequence?
8, -16, 32, -64, ...

Answer 1

a_1rn

Answer 2

can any of you guys help me with my assignment?

Answer 3

these are the answers available???
an=-1(3)n − 1
an=1(-3)n − 1
an=3(-1)n − 1
an=3(-3)n − 1

Answer 4

not sure... i thoght the ratio was -2

Answer 5

personally i thought the geometric sequence was

\[a_1r^n=8(-2)^n\]

Answer 6

A geometric sequence or a geometric progression is represented by

\[a _{n}= ar ^{n-1}\]

Where n is the number of the term, a is the first term and r is the common ratio.

The first term of a geometric sequence is always a, so in your case, that would be 8
Now you need to find 'r'

First term = a = 8
Second term = ar = 8r =-16
Third term = ar^2 = 8r^2 = 32

Divide the second term by the first term and you get r = -2

So the correct answer is =8(−2)^n-1

Answer 7

thanks

Answer 8

that is not an answer -.- though

Answer 9

\[solve for x: x-6\div5-4x+4\div5=3\]