Question

Find an equation for the nth term of the arithmetic sequence.

-15, -6, 3, 12, ...

an = -15 + 9(n + 1)

an = -15 x 9(n - 1)

an = -15 + 9(n + 2)

an = -15 + 9(n - 1)

Answer 1

if n = 1, what do each of those expressions give you?

Answer 2

actually, start with n = 0

it'll give you the answer right off the bat

Answer 3

I got A?

Answer 4

wait. C? @AllTehMaffs

Answer 5

nevermind. I got it. it was A. thank you :) but would I go about doing the same thing for this one?

Find an equation for the nth term of the arithmetic sequence.

a14 = -33, a15 = 9

an = -579 + 42(n + 1)

an = -579 + 42(n - 1)

an = -579 - 42(n + 1)

an = -579 - 42(n - 1)

Answer 6

yeah, just plug in "14" and "15" into the given functions to see which come out as

-33 for n=14

and

9 for n=15

^_^