已知实数x ,y 满足x^2+3x+y-3=0,则x+y的最大值为?二次函数性质那的题

已知实数x,y满足x-y 已知实数X,Y满足{|x+y| 已知实数x,y满足约束条件x+y>3,y 已知实数X,Y满足2 已知实数xy满足x+2y 已知实数xy满足 x+y-2 已知实数x.y满足(x+2)^2+y^2( 已知实数x,y满足：y 已知实数x,y满足2x+5y>=10;2x-3y>-6;2x+y 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 已知实数x,y满足x^2+3X+y-3=0,则x+y的最大值为 已知实数x,y满足y=x^2+5x-4,则3x-2y最大值为 已知实数x,y满足x²-x+y=2,则3x-y的最小值为_______. 已知实数x,y满足不等式组：2x-y=0,x+2y 已知实数x,y满足约束条件:x>=2 y>=2 x+y 已知实数x,y满足x+y>=2,x-y 已知实数X,Y满足X+Y>=2,X-Y 已知实数x,y满足y=|x-1|,则x+2y的最大值是