Question

Write an equation for the nth term of each geometric sequence.

-1, -5, -25,...
Oa. an = (5)-¹-1
Ob. a , = - 1¹( 3 ) - ²
5
Oc. an =-1(5)n-1
Od. an = 1(5)n-1

Answer 1

C

Explanation:

the nth term of a geometric sequence is

`a_(n)` = a₁
`r^(n-1)`

where a₁ is the first term and r the common ratio

here a₁ = - 1 and r =
`(a_(2) )/(a_(1) )` =
`(-5)/(-1)` = 5

then nth term is

`a_(n)` = - 1
`(5)^(n-1)`