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ratia unei progresii geometrice daca am b4=27

Răspuns :

[tex]\dfrac{..}{..}\ \ b_4=27,\ b_7 = 729[/tex]

[tex]b_7=b_4\cdot q^3 \Longrightarrow q^3=\dfrac{b_7}{b_4} = \dfrac{729}{27} =27[/tex]

[tex]q^3=27 \Longrightarrow q^3=3^3 \Longrightarrow q=3[/tex]

[tex]b_1=\dfrac{b_4}{q^3} =\dfrac{27}{27} = 1[/tex]