{х^2-у^2=-3,х-у=3; {х^2-4ху+у^2=6,у-2х=3; Помогите пожалуйста

№1

$\left \{ {{ x^{2}- y^{2}=-3 } \atop {x-y=3}} \right. \left \{ {{ x^{2} - y^{2}=-3 } \atop {x=y+3}} \right.$

$(y+3)^{2} - y^{2} =-3$
$y^{2} +6y+9- y^{2}=-3$
$6y=-12$
$y = -12:6$
$y = -2$

$x = -2 +3=1$

№2

$\left \{ {{ x^{2} -4xy+ y^{2}=6 } \atop {y-2x=3}} \right. \left \{ {{ x^{2} -4xy+ y^{2}=6 } \atop {y=2x+3}} \right.$

$x^{2} -4x*(2x+3)+ (2x+3)^{2}=6$
$x^{2} -8x^{2}-12x+4 x^{2} +12x+9=6$
$-3 x^{2} =-3$
$x^{2} =-3:(-3)$
$x^{2} =1$
$x=1$

$y =2*1+3=5$