Question

Find the sum of an infinite geometric series with the first term 8 and the fourth term 27 .​

Answer 1

Answer:

-16

Step-by-step explanation:

first term(a) = 8 

fourth term = 27 

ar^3=27

8× r^3 =27

r^3= 27÷8

r^3= (3/2)^3

r=3/2

sum of an infinite geometric series

= a/(1-r)

= 8/(1-3/2)

=8 ÷ (-1/2)

= 8 × -2

= -16