Question

Questão de prova gente!!!

Answer 1

Resposta:

$a_9=1$

Explicação passo-a-passo:

$PA = (a_1;a_2;a_3;a_4;\dots)=(41;36;31;26;\dots)\\\\ a_n=a_k+(n-k)r\ \therefore\ a_2=a_1+(2-1)r\ \therefore\\\\ 36=41+r\ \therefore\ r=-5\\\\ a_9=a_1+(9-1)r\ \therefore\ a_9=41+8(-5)\ \therefore\\\\ a_9=1$

Letra C.

Answer 2

Resposta:

Explicação passo-a-passo:

formula =  A' = a' + (n-1) .r

A'= 41 + ( 9-1). -5

A' = 41 + 8. -5

A' = 1