The terms 140, a, \(560\) are the first, second and third terms, respectively, of a geometric sequence. If a is positive, what is the value of a ?

Guest Jan 30, 2022

#1**0 **

geometric sequence in general: a, ar, ar^2, ...

where a is the first term and r is the common ratio.

140 = a

560 = ar^2

Divide to get 4 = r^2, or r = 2. So, the second term is 140 * 2 = **280.**

CubeyThePenguin Jan 30, 2022