已知z=2x+y,x,y满足y≥x,x+y≤ 2,x≥m,且z的最大值是最小值的4倍,则m的值是.

已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知x、y、z满足方程组：x+y-z=6；y+z-x=2；z+x-y=0 求x、y、z的值 已知X.Y.Z满足方程组,X+y-Z=6y+z-x=2z+x-y=0求X.Y.Z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知整数x、y、z,满足x≤y＜z,且｜x+y｜+｜y+z｜+｜z+x｜=4,｜x-y｜+｜y-z｜+｜z-x｜=2,求x^2+y^2+z^2的值. 已知整数x,y,z满足x≤y＜z,且|x+y|+|y+z|+|z+x|=4 |x-y|+|y-z|+|z-x|=2 那么x²+y²+z²的值 已知实数x,y,z,满足那么x+y=6,z^2=xy-9,求(x+y)^z 已知x,y,z,满足方程组x-2y+z=0,7x+4y-5z=0 已知x,y,z满足方程组｛x+y-z=6{y+z-x=2{z+x_y=0,求x,y,z的值 设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y 已知整数x,y,z满足(x-y)(y-z)(z-x)=x+y+z,证明:x+y+z是27的倍数 已知实数X,Y,Z,满足X^2-2X+Y=Z-1,且X+Y^2+1=0,试比较X,Y,Z的大小. 已知x,y,z满足2/x=3/y-z=5/z+x,则5x-y/y+2x的值快快 已知x,y,z满足方程组：4x-5y+2z=o;x+4y-3x=0,求x:y:z的值 已知z不等于0,x、y、z满足4x-7y-5x=0,2x-y-z=0.求x：y 已知x,y,z满足4x+11y=5x,2x+y=z求x:y:z 已知实数x,y满足条件 y≤0,y≥x,2x+y+4≥0,则z=x+3y的最小值是 已知x,y满足约束条件｛x+y+1≤0,x-y+1≥0,y+1≥0,则z=2x-y的最大值是?