3x+2y+6z=61 3x+5z=44 2y+5x=25 5z+7y=70 求 x=? y=? z=?
x/2=y/3=z/5 x+3y-z/x-3y+z
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
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=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
3x+2y+6z=61 3x+5z=44 2y+5x=25 5z+7y=70 求 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)