x-2y+4z=0 x+3y-7z=1 则2x+y-3z的值为?

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x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值 4x-3y-6z=0,x+2y-7z=0是一个方程组,那么x-y+z/x+y+z的值等于 若4x=7y+5z,2x+y=z,则x:y:z的值为 若2x+5y-4z=0,3x+9y-7z=0,则x+y-z的值为 若x-2y+4z=1,x+3y-7z=0,则y:z=? 若x/2=y/3=z/4不等于0,求x+y+z/x+y-z的值 已知4x-3y-6y=0,x+2y-7z=0.求x-y+z\x+y+z的值 x=2,y=-3,z=3则表达式x||y+z&&y-z的值为 2x+5y+4z=0,3x+y-7z=0,则x+y-z=? 已知3x+2y-3z=0 8x-4y-z=0 其中z不等于0,则x:y:z=0,则x:y:z的值为()