Question

Given the sequence -1, 2, -4, 8.... What is the 10th term? Write the number only.

Answer 1

This has a formula to this

Answer 2

Well first you have to find the common ratio

Answer 3

-1 * -2 = 2

2 * -2 = -4

-4 * -2 = 8

8 * -2 = -16

-16 * -2 = 32

you just multiply the last number in the sequence by -2 each time :)

Answer 4

okay

Answer 5

-16. 32, -64, 128, -256, 512 is the answer [512]

Answer 6

There actually is a formula. an = a1*r^(n-1)

Answer 7

@ComputerNerd Like i said, its a arithmetic sequence

Answer 8

It has a formula

Answer 9

a1 is the first number in sequence

Answer 10

@hybrik its actually a geometric sequence

Answer 11

Write the common ratio for the sequence: 12,6,3,\frac{3}{2},...

Write the number only.


I'm stuck on this one as well

Answer 12

"\frac{3}{2}"?

Answer 13

3/2

Answer 14

The ratio is 1/2

Answer 15

Either you can do this logically or the arithmetic sequence formula

Answer 16

Identify the 10th term for the sequence: 12,6,3,\frac{3}{2},...

Write the answer as an integer or fraction.


I'm stuck on this one as well

Answer 17

it's the same pattern as the other

Answer 18

@ComputerNerd I noticed when I was using the formula

Answer 19

XD

Answer 20

3/4, 3/8, 3/16, 3/32, 3/64, 3/128 is the answer, 3/128, by the way, Geometric sequences have to do with Multiplying/Dividing patterns, Arithmetic has to do with Adding / Subtracting

Answer 21

or you could just do it the easy way @Aliypop and do what I said... Lol
@ComputerNerd you don't always need to do the formula if there's a simpler way

Answer 22

@Jadeishere It's always best to know the formula. Your method is okay for terms lower in the sequence but would take too long for terms like 100th term.

Answer 23

okay