2x+y+3z=14 x-y+z=4 3x-y-z=2
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
x/2=y/3=z/5 x+3y-z/x-3y+z
已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=?
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
1.x+y=16,y+z=12,z+x=102.3x-y+z=4,2x+3y-z=12,x+y+z=63.x+y+z=6
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
x+2y+3z=14 2x+y+z=7 3x+y+2z=11
3x+2y+z=14 x+y+2z+-3 2x+3y-z=1
3x+2y+z=14 ,x+y+z=10,z+2x+3y=1 5
[3x+2y+z=14,x+y+z=10,2x+3y-z=1]