Question

Qual ea posicao do termo 109 em. Uma p.a. de razao 3, cujo1 termo e10

Answer 1

$\sf a_n=a_1+(n-1)r$

$\sf 109=10+(n-1)3$

$\sf 109=10+3n-3$

$\sf 109-10+3=3n$

$\sf 102=3n$

$\sf n=\dfrac{102}{3}$

$\red{\sf n=34}$