满足X+2Y-6≤0 2X+Y-6≤0 X≥0 Y≥0 则目标函数Z=2X-Y的最大值为?

求f(x,y)=x+y+7的最大值,使(x,y)满足x+2y≤10,2x+y≥6,y≥0 已知非负实数x,y满足2x+3y-6≤0 且3x+2y-6≤0,则x+y的最大值是? 已知x,y满足x+y-6≤0,x+2y-8≤0,2x-3y-6≤0,x≥0,0≤y≤3,求(3y-12)/(x-6)的最大值和最小值. 实数x,y满足2x+5y>=0,2x-3y>=-6,2x+y 已知x,y满足x^2+y^2-6x+8y+25=0,求y^x的值 已知x、y满足：x^2+y^2+6x-10y+34=0,求y-x的值 如果有理数x.y满足x^2+y^2+4x-6y+13=0,则y^x=? 已知实数x, y满足x²+y²-2x+6y+10=0,求y∧-x. 求f(x.y)=x+6y+7的最大值,使(x.y)满足 (1) x+2y≤10 (2) 2X+y≥6 (3) y≥0需要准确的过程 设变量xy满足约束条件x-y≥0,x+y-2≥0,3x-y-6≤0则目标函数z=2x-y设变量xy满足约束条件x-y≥0,x+y-2≥0,3x-y-6≤0则目标函数z=2x-y的最小值为（ ）. 已知实数x,y满足(x-y+6)(x+y-6)≥0,1≤x≤4,(1)求x^2+y^(2)-2的取值范围,(2)求y/(x-3)的取值范围. 变量x,y满足x-2y=0,x y满足x-y+2≥0,x+y-4≥0,2x-y-5≤0 求X^2+Y^2-10Y+25的最小值 已知x.y满足(x-y-2≤0,x 2y-5≥0,y-2≤0 则3x+y/x+1得多少 化简求值：已知x、y满足：x^2+y^2-4x+6y+13=0 求代数式 的值.(3x+y)^2-3(3x-y)(x+y)-(x-3y)(x+3y)急用！ 实数x,y满足条件x+y-4≤0,x-2y+2≥0,x≥0,y≥0,则x-y的最小值为 已知实数x,y满足不等式组x≥0,y≥0,x+y≤1,则x^2+y^2-2x-2y的最小值 设变量x,y满足约束条件 {x-y≥0,x+y≤1,x+2y≥0},则函数Z=2x+y 的最大值?