Ratia progresiei geometrice se noteaza cu q.
[tex] b_{2}= b_{1}*q \\ b_{5}=b_{1}* q^{4} [/tex]
Daca se impart cele doua relatii, se obtine:
[tex] \frac{b_{2} }{ b_{5} } = \frac{q}{ q^{4} } = \frac{1}{ q^{3} } => \frac{1}{8}= \frac{1}{ q^{3} } => q^{3}=8 =>q=2 [/tex]
