Question

Find an equation for the nth term of the sequence.

-3, -12, -48, -192, ...

an = 4 • -3n + 1

an = -3 • 4n - 1

an = -3 • 4n

an = 4 • -3n

Answer 1

did you see any pattern in your sequence ?

Answer 2

it was times 4

Answer 3

yep!
next term is 4 times current term!
so its a geometric sequence.
heard about it ?

Answer 4

i have heard of it. just dont know what to do from there

Answer 5

ok, so general term is
\(\Large a_n= a_1r^{n-1}\)

Answer 6

where a1 is the 1st term, r = common ratio

Answer 7

r = next term by current term = 4 here

Answer 8

a1 = 1st term = -3 here
just plug these in the formula!

Answer 9

thank you so much !

Answer 10

oh, you got it ?which option/choice?

Answer 11

the second one

Answer 12

correct :)