X^2 + 2xy + y^2 -4x -4y = 45 x^2 - 2xy + y^2 - 2x +2y = 3

Решите задачу:

$\left \{ {{x^2+2xy+y^2-4x-4y=45} \atop {x^2-2xy+y^2-2x+2y=3}} \right. \; \; \; \left \{ {{(x+y)^2-4(x+y)=45} \atop {(x-y)^2-2(x-y)=3}} \right. \\\\t=x+y\; ,\; \; t^2-4t-45=0\; ,\; t_1=-5,\; t_2=9\\\\p=x-y\; ,\; \; p^2-2p-3=0\; ,\; p_1=-1,\; p_2=3\\\\ a)\quad\left \{ {{x+y=-5} \atop {x-y=-1}} \right. \; \left \{ {{2x=-6} \atop {2y=-4}} \right. \; \left \{ {{x=-3} \atop {y=-2}} \right.$

$b)\quad \left \{ {{x+y=-5} \atop {x-y=3}} \right. \; \left \{ {{2x=-2} \atop {2y=-8}} \right. \; \left \{ {{x=-1} \atop {y=-4}} \right. \\\\c)\quad \left \{ {{x+y=9} \atop {x-y=-1}} \right. \; \left \{ {{2x=8} \atop {2y=10}} \right. \; \left \{ {{x=4} \atop {y=5}} \right. \\\\d)\quad \left \{ {{x+y=9} \atop {x-y=3}} \right. \; \left \{ {{2x=12} \atop {2y=6}} \right. \; \left \{ {{x=6} \atop {y=3}} \right. \\\\Otvet:\;(-3,-2)\; ,\; (-1,-4)\; ,\; (4,5)\; ,\; (6,3)\; .$