Respuesta :

Answer:

first term(a)= 80

common ratio(r)= t2/t1 =40/80 =1/2

T4= ar^n-1

= 80*1/2^4-1

=80*1/2^3

=80*1/8

=10

then

t5=ar^n-1

= 80*1/2^5-1

=80*1/16

=5