Question

!!NEED HELP!!

The formula a subscript n = 10 - 4n describes an arithmetic sequence. What are the first four
terms in the sequence?

A)6, 2, -2,-6

B) 6,2,0,-2

C)10, 6, 2,-2

D)14, 18, 22, 26

Answer 1

A)6, 2, -2,-6

Explanation:

a(n) = a +(n-1)d

a(n) = a +dn-d

a(n) = a-d + dn

a(n) = 10 - 4n

So d=-4

to get a: (a-d)=10

a=10-4=6

The first four terms:

a(1) = 6 +(1-1)-4=6

a(2) = 6 +(2-1)-4=2

a(3) = 6 +(3-1)-4=-2

a(4) = 6 +(4-1)-4=-6

it will be A

hope this helps