Решите систему: x-y=2 x^2-xy+y^2=7
X=2+y, x-y=2, x-y=2, x-y=2, x=y+2, x=y+2, x=y+2, x=y+2, x²-xy+y²=7, (x²-2xy+y²)+xy=7, (x-y)²+xy=7, 4+xy=7, xy=3, (y+2)y=3, y²+2y-3=0, [y=-3, y=1, [ {y=-3, x=-1, {y=1, x=3. Ответ: (-1;-3);(3;1)