Sequence Question

Question

What is the 8th term in the sequence 3,2,0,-4,-12,...?

 

a. -124

b. -60

c. -36

d. -144

Answer 1

3,2,0,-4,-12

 

3

3-1 =2 ... 3-2⁰

2-2 =0 ... 2-2¹

0-4 =-4... 0-2²

-4-8=-12... -4-2³

Each time we are subtracting powers of 2

 

-12-2⁴ = -12-16=-28

-28-2⁵ = -28-32 = -60

-60-2⁶ = -60-64 = -124

 

answer a