Question

20 puncte + coroana!!!
$\left \{ {{ \frac{x}{y} - \frac{y}{x} = \frac{5}{6} } \atop { x^{2} - y^{2} = 5 }} \right.$

Answer 1

x²/xy - y²/xy=5/6
(x²-y²)/xy=5/6
5/xy=5/6 ⇒ xy=6 
x²-y²=5
(x-y)* (x+y) =5
x=3 si y=2
x=-3 si y=-2