Question

Quantos termos tem a P.A. (5, 9, 13,..,157)? *

0 pontos

(A) 35

(B) 36

(C) 37

(D) 38

(E) 39​

Answer 1

(E) 39

Cálculo:

r= 9 - 5

r= 4

an = a1 + (n-1) . r

157 = 5 + (n-1) . 4

157= 5 + 4n - 4

152 = 4n - 4

156 = 4n

156 ÷ 4 = n

39 = n