a + b + c = 130
a / 1 /2 = b/1/3 = c /1/4 = k ⇒ a = k/2; b = k/3; c = k/4
k/2 + k/3 + k/4 = 130
cmmmc al numerelor ( 2, 3, 4) = 12
→ le aduc la acelasi numitor comun 12
6 k + 4 k + 3 k = 12 × 130
13 k = 12 × 130 l : 13
k = 12 × 10 = 120
a = 120 / 2 = 60
b = 120 / 3 = 40
c = 120/4 = 30
Verific: 60 + 40 + 30 = 130 → suma celor trei numere
