设x>=0,y>=0,2x+y=6,求Z=(4x^2)+3xy+(y^2)-6x-3y的最值

设X+Y+Z=0求X^3+X^2Z-XYZ+Y^2Z+Y^3的值 设z=ln(x+y/2x),求{əz／əy]l(1,0) 设z≠0 x、y、z 满足4x-7y-5z=0 2x-y-z=0 求x：y 设z≠0,x、y、z满足4x-7y-5z=0、2x-y-z=0,求x:y 一道初2数学题目 运用设K解决 速度已知(y+z)/x=(z+x)/y=(x+y)/z (x+y+z≠0) 求(x+y-z)/(x+y+z)的值 已知：x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值 设z=z(x,y)由yz+x^2+z=0确定,求dz(x,y) 设Z=X+Y,其中X,Y满足X+2Y>=0,X-Y 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 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 设x+y+z=0,求x立方+x平方z-xyz+y平方z+y立方 设 x+2y+z-2根号下xyz=0 求∂z/∂x ,∂z/∂y 设函数z=z(x,y)由方程x^2+y^3-xyz^1=0确定,求z/x,z/y 设变量x,y,z满足x+y+z=1 0≤x≤1 0≤y≤2 3y+z≥0求F=3x+6y+4z的最大值和最小值 设变量x,y,z满足约束条件：x+y+z=1,0≤x≤1,0≤y≤2,3y+z≥2,求F=3x+6y+4z的最大值. 设xyz不 等于0,且2x-y+z=0,x+2y-5z=0,试求代数式(x-y)/(y+z) 的值