Question

Gente eu preciso de ajuda na questão 3

Answer 1

Resposta:

Item d)

Explicação passo-a-passo:

$\dfrac{3^{n+3}-3.3^{n-1}}{3.3^{n+2}}=\dfrac{3^{n+3}-3^{n-1+1}}{3^{n+2+1}}=\dfrac{3^{n+3}-3^{n}}{3^{n+3}}=$

$=\dfrac{3^{n+3}}{3^{n+3}}-\dfrac{3^{n}}{3^{n+3}}=1-3^{n-(n+3)}=1-3^{n-n-3}=\\\\\\=1-3^{-3}=1-\dfrac{1}{3^{3}}=1-\dfrac{1}{27}=\dfrac{27-1}{27}=\dfrac{26}{27}$