已知x:y:z=3:4:7,且2x—y+z=-18,求式子x+2y-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:y:z=2:3:4,且x-y+z=36,求x+y+z的值.
已知x+y/2=y+z/3=z+x/4,且x+2y+z=12,求x-2y+z的值
已知x/2=y/3=z/4,且x+y+z不等于0,求2x+3y-4z/x+y+z的值
已知x :y :z=3:4:7,且2x-y+z= -18,求x+2y-3z的值.
已知4x-3y-6z=0,x+2y-7z=0,且x、y、z都不为0,求(3x+2y+z)/(x+2y+3z)的值 快帮求
已知4x-3y-6z=0 ① ,x+2y-7z=0 ②,且x,y,z均不为0,求3x+2y+z÷x+2y+3z的值
已知4x-3y-6z=0,x+2y-7z=0,且x,y,z≠0,求2x+3y+6z/x+5y+5z的值.
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
已知x=y/3=z/5.且x+y-2z不等于0.求2x+3y-z/x+y-2z的值是多少
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.
已知x:y:z=2:3:4,且3x+2y+z= —32,求x+2y+3z的值