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:

$a_n = a \times r^{n-1}$

Therefore, the 14th term is :

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

Hope it helps!