Disediakan susunan bilangan 59, 47, 35, a, b, -1

Diket susunan bilangan 59, 47, 35, a, b, -1 (merupakan barisan aritmatika)
Jadi, U1 = 59, b = 47-59 = -12, n = 5
Mencari a = U4
U4 = U1 + (n-1) × b
U4 = 59 + (4-1) × (-12)
U4 = 59 + 3 × (-12)
U4 = 59 + (-36)
U4 = 23
Mencari b = U5
U5 = U1 + (n-1) × b
U5 = 59 + (5-1) × (-12)
U5 = 59 + 4 × (-12)
U5 = 59 + (-48)
U5 = 11
Jadi nilai a = 23 dan b = 11
Susunan bilangan nya: 59,47,35,23,11,-1