Question

The 7th term of a geometric progression is 48 the 8th term is -16 find the common ratio

Answer 1

r = -
`(1)/(3)`

Explanation:

The common ratio r is calculated as

r =
`(a_(8) )/(a_(7) )` =
`(-16)/(48)` = -
`(1)/(3)`

Answer 2

48 = 768* (r)^2

thus, r = 0.25

solving for a(7)

a(7) = 768 * (0.25)^(5)

a(7) = 0.75

Explanation: