Question

What is the sum of the geometric sequence 1, -6, 36, ... If there are 6 terms? (1 point)

Answer 1

Answer:

-6665

Step-by-step explanation:

The given GP is :

1, -6, 36, ...

Number of terms = 6

The sum of n terms of a GP is given by :

$S_n=\dfrac{a(r^n-1)}{r-1}$

Here,

a = 1, n = 6, r = 36/-6 = -6

So,

$S_6=\dfrac{1((-6)^6-1)}{(-6)-1}\\\\=-6665$

So, the sum of th GP is -6665.