Question

Find the 7th term in the
sequence
-4, -8,-16, . . .

Answer 1

Answer: -512

Explanation:

to answer this problem you need to understand the sequence and hen extrapolate the sequence out until you get to the seventh term (which would be your answer).

looking at -4, -8, -16

First we clearly see that each number is a negative and an even number. going beyond this we see -4 goes into -8 twice and -8 goes into -16 twice (in other words the next number in the sequence is always double the proceeding number). Also, each number is an even factor of four which can help us with double checking at the end!

1. -4 --> (-4) + (-4) = -8
2. -8 --> (-8) + (-8) = -16
3. -16 --> (-16) + (-16) = -32
4. -32 --> (-32) + (-32) = -64
5. -64 --> (-64) + (-64) = (-120) + (-8) = -128
6. -128 --> (-128) + (-128) = (-200) + (-40) + (-16) = -256
7. -256 --> (-256) + (-256) = (-400)+(-100)+(-12) = -512

Can also be seen as:

1. 4 times (-2) = -8
2. 4 times (-4)= -16
3. 4 times (-8) = -32
4. 4 times (-16) = -64
5. 4 times (-32) = -128
6. 4 times (-64) = -256
7. 4 times (-128) = -512

Double check by going back and reviewing you math as well as making sure each answer is even and divisible should be divisible by four!

I hope this helps!

P.S.

As this addition is rather tedious you could also times each previous answer by 2 .

example:

-64 times 2 = -128

(previous number in sequence) times 2 = (next number in sequence)