С праздником пацаны!! помогите мне плиз с алгеброй

Решите задачу:

$\left \{ {{x^2-xy+y^2=63} \atop {x-y=-3}} \right. , x=y-3\\ (y-3)^2-y(y-3)+y^2=63\\ y^2-6y+9-y^2+3y+y^2-63=0\\ y^2-3y-54=0\\ y_1=9, y_2=-6\\x_1=9-3=6, x_2=-6-3=-9\\ Otvet: (6, 9), (-9, -6)$

$\left \{ {{x^2+y^2+x+y=2} \atop {2x^2-y^2+2x-y=4}} \right. , \left \{ {{x(x+1)+y(y+1)=2} \atop {2x(x+1)-y(y+1)=4}} \right. , skladyvaem !uravneniya!\\ 3x(x+1)=6\\ x(x+1)=2\\ x^2+x-2=0\\ x_1=-2, x_2=1\\\\ x_1=-2\\-2*(-1)+y(y+1)=2\\2+y(y+1)=2\\ y(y+1)=0\\y=0, y=-1\\(-2,0), (-2,-1)\\\\ x_2=1\\1*2+y(y+1)=2\\2+y(y+1)=2\\y(y+1)=0\\y=0,y=-1\\(1,0), (1,-1)\\\\Otvet: (-2,0), (-2,-1), (1,0), (1,-1)$