Question

Use the information given to identify the a7 term of the geometric sequence: a2 = −5, r = 2

Answer 1

`a_(7)` = - 160

Explanation:

The n th term of a geometric sequence is calculated as

`a_(n)` = a₁
`(r)^(n-1)`

where a₁ is the first term and r the common ratio

Given

a₂ = - 5, then

a₁r = - 5, that is

2a₁ = - 5 ⇒ a₁ = - 2.5, thus

`a_(7)` = - 2.5 ×
`(2)^(6)` = - 2.5 × 64 = - 160