已知|X—Z|+|2Y+B|=0,求（2X—3Y）×（2X+3Y）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. 已知x、y、z满足x—2y+z=0 7x+4y—5z=0 ,求x：y：z 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)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 已知 3x-y+2z=0 2x+y-3z=0,求x :y :z. 已知（1）X-Y+Z=0 (2)X+2Y-3Z=0 求X:Y:Z 已知｛2x-y-z=0,3x-9y+z=0求1,x:y:z 已知{x-5y+2z=0 3x-5y-4z=0,求x：y:z 已知｛X-Y+Z=0,X+2Y-3Z=0求X：Y：Z的值 已知{x-y+z=0,x+2y-3z=0},求x:y:z 已知z、y、z同时满足x+3y-5z=0,2x-y-3z=0,求x:y:z 已知x+y+z=0,xyz=2,求|x|+|y|+|z|的最小值 已知方程组4x-3y-2z=0,x-3y+z=0,z≠0求x/z,y/z的值 已知x+y-7z=0 x-2y+5z=0(xyz不等于0）,求x+2y-z/y-2x+12z 已知x+y-z=0,2x-y+2z=0 求（3x-2y+5z)/(5x-3y+2z)的值 已知xyz不等于0,且x+2y-z=0,7x-y-z=0,求x+y+z/2x-y-z的值.