{(x+y)/(x-y)=5
{x² +y² =13
{x+y = 5(x-y)
{x²+y²=13
{x+y = 5x-5y
{x²+y²= 13
{x+y -5x+5y =0
{x²+y²=13
{-4x+6y = 0
{x² +y²=13
{x=6y/4
{x²+y²=13
(6y/4)² + y²=13
36y²/16 + y² = 13 |* 16
36y²+16y²= 208
52y²=208
y²= 208/52
y=√4
y₁= 2 x₁= (6*2)/4= 12/4=3
y₂= -2 x₂= (6* (-2)) /4 = -12/4=-3
Ответ : (3;2) и ( -3;-2)