Question

na P.A de a1= -3 e r= 3 sobre 2
calcule:
a) a10 b) a39

Answer 1

Olá.

$\boxed{\boxed{a_n=a_1+(n-1)\cdot r}}\\\\\\\\a_{10}=-3+(10-1)\cdot\dfrac{3}{2}\\\\a_{10}=-3+9\cdot\dfrac{3}{2}\\\\a_{10}=-3+\dfrac{27}{2}\\\\a_{10}=\dfrac{2\cdot(-3)+27}{2}\\\\a_{10}=\dfrac{-6+27}{2}\\\\\boxed{a_{10}=\dfrac{21}{2}}\\\\\\a_{39}=-3+(39-1)\cdot\dfrac{3}{2}\\\\a_{39}=-3+38\cdot\dfrac{3}{2}\\\\a_{39}=-3+\dfrac{114}{2}\\\\a_{39}=-3+57\\\\\boxed{a_{39}=54}$

A imagem é pra caso o LaTex falhe.
Qualquer dúvida, deixe nos comentários.
Bons estudos.