已知x:y:z=2:3:4,求x-y-z/3x+2y-z的值.若2x+3y-4z=-3,求3x-4y-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x/3=y/4=z/2,求x+2y-z/x+y+z=? 已知X:Y:Z=3:4:5,求4X+3Y-2Z/X+Y+Z的值 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值 已知x/4=y/5=z/6,求x+y+z/3x-2y+z的值. 已知x:y:z=2:3:4,且x-y+z=36,求x+y+z的值. 已知x:y:z=2:3:4且x+z-y=36求x+y+z的值 已知x:y:z=2:3:4,且x+z-y=36.求x+y+z的值 已知x:y:z=2:3:4,且x+y+z=18.求x、y、z的值. 已知{x-5y+2z=0 3x-5y-4z=0,求x：y:z 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=3：4：5,(1)求x+y分之z的值；（2）若x+y+z=6,求x,y,z. x+2y=3x+2z=4y+z 求x:y:z 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^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+2y+3z=2,3x+y+2z=3,2x+3y+z=4,求x+y+z的值