{2x+y=3,3x-y+z=8,x+2y+z=13
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
x/2=y/3=z/5 x+3y-z/x-3y+z
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
解三元一次方程:x+y-z=0,2x+y+z=7,x-3y+z=8
①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z-
3x+2y+z=13 x+y+2z=7 2x+3y-z=12 x=?y=?z=?
{3x+2y+z=13 x+y+2z=7 2x+3y-z=12,求x,y,z