X+Y+Z=20,4X+3Y-Z=14.3X+4Y-2Z=16

x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 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 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)(x-y+z)= (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai x+y+z=2 4x+2y+z=4 2x+3y+z=1 解方程：{2x+3y+z=7,x+y+z=4,3x+y-z=-4 x-y+4z=10,x+3y+2z=2,x+2y+3z=11. x+2y+3z=10,x-y+4z=10,x+3y+2z=2 x+y+z=4 2x+3y-z=6 3x+2y+2z=10 已知,x/2=y/3=z/4,则(2x+y-z)/(3x-2y+z)=? 2x+5y+4z=6,3x+y-7z=-4,x+y-z=?