Question

quantos termos tem a pa(6,13,20...,83)?​

Answer 1

r = 13 - 6 = 7

an = a1 + (n - 1) * r

83 = 6 + (n - 1) * 7

83 - 6 = (n - 1) * 7

77 = (n - 1) * 7

n - 1 = 77/7

n - 1 = 11

n = 11 + 1

n = 12