{x+y+z=12 x+2y-5z=25 3x-2y-4z=8

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 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 ①x+y+z=6 3x-y+2z=12 x-y-3z=-4 ②x+y-z=2 4x-2y+3y+8=0 x+3y-2z- 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, 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X 解方程组{3x+y-z=4,2x-y+3z=12,x+y+z=6} 解方程{3x -y+z=4 2x+3y-z=12 x+y+z=6 x+y+z=51 4x+8y+5z=300 x+y+2z=67