Question

calcule a razão de uma p.g decrescente de cinco termos, sendo o primeiro termo igual a 2/3 e o ultimo igual a 2/243

Answer 1

$Resolu\c{c}\~ao \to \left\{\begin{array}{ccc}a_1= \frac{2}{3};\ a_n=a_5 = \frac{2}{243} \\\\a_n = a_1*q^{n-1}\\\\a_5 = a_1*q^{5-1}\\\\ \frac{2}{243} = \frac{2}{3}*q^{4}\\\\q^{4} = \frac{2*3}{2*243}\\\\q^{4} = \frac{1}{81}\\\\\boxed{\boxed{q= \sqrt[4]{ \frac{1}{81} } = \frac{1}{3} }} \end{array}\right$

Espero ter ajudado. :))