[tex]\it Not\breve am\ frac\c{\it t}iile\ cu\ x\ \d si\ y\ .\\ \\ \\ x+y=\dfrac{8}{7} \ \ \ \ \ (1)\\ \\ \\ \dfrac{x}{y}=\dfrac{3}{5} \Rightarrow 5x=3y|_{+3x} \Rightarrow 8x=3x+3y \Rightarrow 8x=3(x+y)\ \ \ \ \ (2)\\ \\ \\ (1),\ (2) \Rightarrow 8x=3\cdot\dfrac{8}{7}\Big|_{\cdot\dfrac{1}{8}} \Rightarrow x=\dfrac{3}{7}\ \ \ \ \ (3)\\ \\ \\ (1),\ (3) \Rightarrow y=\dfrac{8}{7}-\dfrac{3}{7}=\dfrac{5}{7}[/tex]
