Question

qual é o 10 termo da PA (3,5,7,...)?

Answer 1

A10=A1+9r
A10=3+9.2
A10=3+18
A10=21

Answer 2

$a_n=a_{10}=? \\ a_1=3 \\ n=10 \\ r=5-3=2 \\ \\ Termo~~geral \\ \\ a_n=a_1+(n-1)r \\ \\ a_{10}=3+(10-1)(2) \\ a_{10}=3+(9)(2) \\ a_{10}=3+18 \\ \\ a_{10}=21$