Question

Numa P.G a3 = 18 e a5 = 8.Determine s8

Answer 1

Resposta:

an=a1.q^n-1

a3,a4,a5= 3 termos

8=18.q^3-1

8/18=q²

4/9=q²

q=√4/9

q=2/3

a5,a6,a7,a8 = 4

an=8.(2/3)^4-1

an=8.(2/3)³

an=8.8/27

an=64/27