Question

Find an equation for the nth term of a geometric sequence where the second and fifth terms are -24 and 1536, respectively.

Answer 1

\[t_{n}=a _{1}r ^{n-1}\]
\[where ~a _{1}~is~the~first~number~and~r~is~the~common~ratio.\]

Answer 2

\[t _{2}=-24,t _{5}=1536\]

Answer 3

ok so now what? plug it in ?

Answer 4

make two equations with above mentioned formula where n=2 and n=5
find r and then a1

Answer 5

im so confused...

Answer 6

\[-24=a _{1}r ^{2-1}=a _{1}r ....(1)\]
\[1536=a _{1}r ^{5-1}=a _{1}r^4 ...(2)\]
divide (2) by (1) and find r

Answer 7

can you do further?