若x:3=y:4=z:5,且3x-2y+2z=18,则2x+5y-3z=多少
若x:3=y:4=z:5,且3x-2y+2z=18,则2x+5y-3z=多少
若2分之x+y=3分之y+z=5分之x+z 且x+y+z=18 求x,y,z的值
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x*x+2y*y+5z*z/5x*x+y*y-
x/2=y/3=z/5 x+3y-z/x-3y+z
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z都不为0,求(3x*x+y*y+4z*z)/(5x*x+y*
已知x:y:z=2:3:4,且x+y+z=18,求x,y,z的值
若x/3=y/2=z/5,则2x-3y-z/x-y+z=
若x/3=y/4=z/5,求x+y+z/3x-2y+z的值.
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=?
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)