Question

In trei butoaie sunt 210l de vin.In primele doua sunt 130l,iar in ultimele doua 150l.Cati l de vin sunt in fiecare butoi?

Answer 1

x-primul butoi
y-al doilea butoi
z-al treilea butoi
x+y+z=210
x+y=130
y+z=150
130+z=210 => z=80 l
y+80=150 => y=70 l
x+70=130 => x=60 l

Answer 2

a+b+c=210 
a+b=130
b+c=150  
210 - c = 130    c=120-130 = 80 
b+80=150       b = 150-80= 70 
a+70 = 130      a=130-70=60