Alin = x
Mircea = y
Cornel = z
A. y=4x
B. y=2z
C. y-z=18
Daca avem y-z=18, inseamna ca y=18+z
Inlocuim in B si obtinem ecuatia urmatoare:
18+z=2z
z=18
=> y=18+z => y=18+18 => y=36
y=4x => 36 = 4x
x=9
Alin = 9kg struguri
Mircea = 36kg struguri
Cornel = 18kg struguri