{ a ; b ; c ; d } d.p { 2 ; 3 ; 4 ; 6 }
d - c + b - a = 12
a / 2 = b / 3 = c / 4 = d / 6 = k
a / 2 = k => a = 2 k
b / 3 = k => b = 3 k
c / 4 = k => c = 4 k
d / 6 = k => d = 6 k
6 k - 4 k + 3 k - 2 k = 12
3 k = 12 | : 3
k = 4
a = 2 × 4 = 8
b = 3 × 4 = 12
c = 4 × 4 = 16
d = 6 × 4 = 24