Question

Determine o 13 Termo da PA (4,-7, -15, -23)

Answer 1

Resposta:

$a_n=a_{13}=?\\ a_1=1\\ n=13\\ r=-7-(1)=-7-1=-8\\ \\ Termo~~geral\\ \\ a_n=a_1+(n-1)r\\ \\ a_{13}=1+(13-1)(-8)\\ a_{13}=1+(12)(-8)\\ a_{13}=1+(-96)\\ a_{13}=1-96\\ \\ a_{13}=-95$