Question

Find the 14th term of the geometric sequence 5,-10,20

Answer 1

In this specific case, the initial term (a) is 5 and the common ratio (r) is -2

Henceforth, after determining what a and r are, we use the formula for the nth term. Which is:

`a_n = a * r^(n-1)`

Therefore, the 14th term is :

`\implies 5 * { (- 2)}^(14 - 1) \\\implies 5 * {( - 2)}^(13) \\ =\boxed { -40,960}`

Hope it helps!