Question

Dertemine um razão de um P.A que tem a1=5 e a12=247

Answer 1

A1 = 5
A12 = A1 + 11r
A12 = 5 + 11r
247 = 5 + 11r
242 = 11r
r = 242/12 = 22
r = 22

Answer 2

an = a1 + (n - 1) . r → a12 = a1 + (n - 1) . r → 247 = 5 + (12 - 1) . r →
247 = 5 + 11 . r → 247 - 5 = 11r → 242 = 11r → 242 = r → r = 22
                                                                        11
P.A. (5, 27, 49, 71, 93, 115, 137, 159, 181, 203, 225, 247)