Question

ajutatima varoog dau coroana

Answer 1

$\frac{x+y}{y} = 10$
$x+y = 10y$ (scădem 2y)
$x-y = 8y$
$\frac{x-y}{y} = 8$
 
$\frac{x-y}{y} \frac{x+y}{y} = \frac{ x^{2}- y^{2}}{ y^{2} } = 10*8 = 80$