已知2x+2y+xy=-2,2y+2z+yz=-1,2z+2x+zx=50,求xyz+2(xy+yz+zx)+4(x+y+z)+8的值

已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z已知XY=2(X+Y),YZ=4(Y+Z),ZX=5(Z+X),求X,Y,Z 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∈R,求证:x^2+y^2>=xy+x+y-1 求全微分函数Z(X,Y),已知方程 Z^2*ln（X+Z)=XY 已知方程组x+2y-z=0,2x-y+8z=0,求x*x+y*y+z*z/xy+yz的值 已知0.5|x-y|+√(2y+z)+(z^2-z+0.25)=0,则z/xy的值是 已知4x-3y=6z 2x+4y=14z 求2xy/x^+y^ 已知4x-3y=6z 2x+4y=14z 求2xy/x^+y^ 已知实数x,y,z满足x=6-y,z^2=xy-9,求证：x=y 已知有理数x,y,z满足x=6-y,z^2=xy-9,说明x=y 已知3x－y+2z=x+2y+3z=0,求（3x^－xy+2y^)/(2x^+4xy+y^)值? 已知（x+y-xy）/(x+y+2xy)=(y+z-2yz)/(y+z+3yz)=(z+x-3zx)/(z+x+4zx),且2/x=3/y-1/z,则xyz=? 已知x-y=5,z-y=10,X^2+Y^2+Z^2-XY-YZ-ZX 已知x-y=a,z-y=10,则代数式x^2+y^2+z^2-xy-yx-zx 已知xy/x+y=3,yz/y+z=2,zx/z+x=1,求y的值 已知XY+X/X+Y+1=2 XZ+2X/X+Z+2=3 (Y+1)(Z+2)/Y+Z+3=4 求X+Y+Z的值已知(XY+X)/(X+Y+1)=2 (XZ+2X)/(X+Z+2)=3 [(Y+1)(Z+2)]/(Y+Z+3)=4 求X+Y+Z的值 代数 x^-y^/ x^-(y-z)^ 除以 x^+2xy+y^/(x-y)^-z^ 乘 x^+xy-xz/x^-xy 已知2x-3y-z=0,x+3y-14z=0(z≠0),求x^2+3xy／y^2+z^2