Proporția:
[tex]\dfrac{y}{x} = \dfrac{7}{5} \implies \dfrac{y}{7} = \dfrac{x}{5} \implies \dfrac{2 x}{2 \cdot 5} = \dfrac{3y}{3 \cdot 7}[/tex]
[tex]\dfrac{2 x}{10} = \dfrac{3y}{21} = \dfrac{2x+3y}{10+21} = \dfrac{62}{31} = 2[/tex]
[tex]\dfrac{y}{7} = 2 \implies \bf y = 14[/tex]
[tex]\dfrac{x}{5} = 2 \implies \bf x = 10[/tex]
