Question

$x^{2} +5 y^{2} -2 y^{2} =-2$
xy=3

Answer 1

$x=frac{3}{y}\ frac{9}{y^2}+5y^2-2y^2 = -2\ 9+5y^4-2y^4=-2y^2\ 9+3y^4=-2y^2\ 3y^4+2y^2+9=0\ y^2=t\ 3t^2+2t+9=0\ D=4-4*3*9<0$
нет решений