x,y满足2x-y=0.y-4=(x+y)^2恒成立,则实数a的最小值

实数x.y满足x平方+y平方-2x+4y=0.则x-2y的最大值 若x.y满足x^2+4x+y^2-10y+29=0.求x+y的值 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 化简求值：2(x+y)(x-2y)-2x(x+y),其中x、y满足x^2+y^2-2x+4y=-5 变量x,y满足约束条件,x+y>=3,x-y>=-1,2x-y 设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 设x,y满足约束条件x+y>=1,x-y>=-1,2x-y 设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y x,y 满足x(x-2)-y(y-6)=-10,求x,y的值 正数x,y满足x-y=2xy,求x-y/x+y的值. 变量x,y满足x-2y=0,x 已知实数x,y满足方程x*x+y*y-4x+1=0.求y-x的最大值 已知实数x,y满足方程x^2+y^2-4x-2y+1=0.求x^2+y^2+x+y的最大值和最小值. .先化简再求值：（2x+y）（2x+y)-(2x-y)平方其中X,Y满足X平方+Y平方-2X+4Y+5=0 已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y 设z=2x+y式中变量x,y同时满足x-4y 若x.y满足条件2x+y-12=0,x-4y+10 已知X和Y满足3X+4Y=2,X-Y-1/7