Question

determine o 71 termo da p.a da sequencia (6,13,20 ..)

Answer 1

a71 = 6 + ( 71 - 1 ) . 7
a71 = 6 + ( 70 ) . 7
a71 = 6 + 490
a71 = 496

Answer 2

$\mathtt{R = A_2 - A_1} \\ \mathtt{R =13 - 6} \\ \mathtt{R = 7 }$

$\mathtt{A_n = A_1 + ( n - 1)~.~R} \\ \mathtt{A_{71} = 6 + ( 71 - 1)~.~7} \\ \mathtt{A_{71} = 6 + 70~.~7} \\ \mathtt{A_{71} = 6 + 490} \\ \mathtt{A_{71} = 496}$

Resposta: 496