2) 4x-9z=17 3x+y+15z=18 x+2y+3z=2 (3) 2x+4y+3z=9 3x-2y+5z=11
2) 4x-9z=17 3x+y+15z=18 x+2y+3z=2 (3) 2x+4y+3z=9 3x-2y+5z=11
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
{4x-9z=17 3x+y+15z=18 x+2y+3z=2
4X-9Z=17 3X+Y+15Z=18 X+2Y+3Z=2
{4x-9z=17{3x+y+15z=18{x+2y+3z=2
(1) 4x-9z=17 3x+y+15z=18 x+2y+3z=2 (2)2x+4y+3z=9 3x-2y+5z=11
x/2=y/3=z/5 x+3y-z/x-3y+z
(1)3x+4z=7;2x+3y+z=9;5x-9y+7z=8 (2)3x+4y+z=14;x+5y+2z=17;2x+
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
4x-5z=17 3x+y+15z=18 x+2y+3z=2
已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/(除以)x-y+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.