x+y=3 y+z=5 x+z=6
(x+y-z)(x-y+z)=
x/2=y/3=z/5 x+3y-z/x-3y+z
已知3X=4X,5Y=6Z求X+Y:Y+Z
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
{2x+3y-4z=-5 x+y+z=6 x-y+3z=10
3x+7y+z=5 ,4x+10y+z=6 ,x+y+z=
解方程组:x+y+z=4,x+y+2z=5,3x+y-z=6
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
5x+3y+2z=2011 4x+6y+7z=2012 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2x+5y+4z=6 3x+y-7z=-4求x+y-z