Question

5) Quantos termos a P.A. (5, 9, 13,…,37) possui?​

Answer 1

Resposta:

$a_n=37\\ a_1=5\\ n=?\\ r=a_2-a_1=9-5=4\\ \\ termo~~geral\\ \\ 37=5+(n-1)(4)\\ \\ 37=5+4n-4\\ \\ 37=1+4n\\ \\ 37-1=4n\\ \\ 36=4n\\ \\ n=36\div4\\ \\ \fbox{ n=9 }$

A P.A possui 9 termos