Răspuns :
[tex]ma = \frac{x + y}{2} \\ x = 3y \\ \\ \frac{3y + y}{2} = 28 \\ \frac{4y}{2} = 28 \\ 2y = 28 \\ y = 28 \div 2 \\ \huge \boxed{y = 14} \\ \\ x = 3y \\ y = 14 \\ x = 3 \times 14 \\ \huge \boxed{x = 42}[/tex]
[tex]ma = \frac{x + y}{2} \\ x = 3y \\ \\ \frac{3y + y}{2} = 28 \\ \frac{4y}{2} = 28 \\ 2y = 28 \\ y = 28 \div 2 \\ \huge \boxed{y = 14} \\ \\ x = 3y \\ y = 14 \\ x = 3 \times 14 \\ \huge \boxed{x = 42}[/tex]