5x+2y-3z 3x-2y+2z=14 4x-2x-5z=9
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=?
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
(1)3x+4z=7;2x+3y+z=9;5x-9y+7z=8 (2)3x+4y+z=14;x+5y+2z=17;2x+
3x+2y+z=14 ,x+y+z=10,z+2x+3y=1 5
{2x+3y-4z=-5 x+y+z=6 x-y+3z=10
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
已知x:y:z=3:4:5,3x+2y-4z=18.求:x+y+z.
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
x/3=y/4=z/5,求x+y+z/3x-2y+z的值,
若x/3=y/4=z/5,求x+y+z/3x-2y+z的值.
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?