Explicație pas cu pas:
[tex]\frac{x}{y} = \frac{2}{3} \iff \frac{x}{2} = \frac{y}{3} = k \\ x = 2k ; \ \ \ y = 3k[/tex]
[tex]\frac{6x + y}{x + 3y} = \frac{6 \cdot 2k + 3k}{2k + 3 \cdot 3k} = \frac{12k + 3k}{2k + 9k} = \frac{15k}{11k} = \bf \frac{15}{11} \\ [/tex]
