Ответ:\((x+2,3)-(x+7,8)=x+2,3-x-7,8=-5,5\).\(-(7,2-y)+(-y+1,6)=-7,2+y-y+1,6=-5,6\).\(-(y-7,4+x)-(11,6-y)=-y+7,4-x-11,6+y=-x-4,2\).\((-2,6+x+y)-(x-y-2,6)=-2,6+x+y-x+y+2,6=2y\).