3x-2x^2+xy-y^2+z^2-5y-4z
化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+(z-y)(x-y)/(xy-2z)(y+z-2x)+(x-
5yz/(y+z)=6,4xy/(z+x)=3,3xy/x+y=2
已知2X-3Y-Z=0,X+3Y-14Z=0,X,Y,Z不全为0,求【4X的平方-5XY+Z的平方】除以【XY+YZ+Z
(x-3y+z)^2+/ 5x-4y+z/=0 且xyz≠0 xy+yz+zx/x^2+y^2+z^2
已知4x-5y+2z=0,x+4y-3z=0,求(x²+y²+z²)/xy+yz+xz
x/2=y/3=z/5 x+3y-z/x-3y+z
已知三个数x,y,z,满足xy/x+y=-2,yz/y+z=4/3,zx/z+x=-4/3,求(xyz)/(xy+yz+
1.(x+y-z)+(x-y+z)-(x-y-z) 2.2x-(3x-2y+3)-(5y-2)
已知X:Y:Z等于3:4:5,求2XY-3XY+Z的平方除以X平方减2XY减Z平方
(2X+Z-Y)/(X^2-XY+XZ-YZ)-(Y-Z)/(X^2-XY-XZ+YZ)
已知x>0,y>0,z>0,证明x^3/(x+y)+y^3/(y+z)+z^3/(z+x)≥(xy+xz+yz)/2
已知2x-3y-z=0.x+3y-14z=0,x,y,z不全为0.求xy+yz+xz分之 4x的平方-(5xy+z)的平