x^2+2y^2+3z^2=6怎么求偏导

请问怎么由2x-3y+z=0 ,3x-2y-6z=0 得到x=3z,y=4z 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 怎么做3元一次方程2x+3y+z=6x-y+2z=1x+2y-z=5 2x+4y+3z=9 3x-2y+5z=11 5x-6y+7z=13 这个方程怎么解? X-7Y+3Z=17和5X-6Y-Z=24和3X+7Y-2Z=1怎么解? x+y+z=6 3x-y+2z=12 x-y-3z=-4这个三元一次方程组怎么解! 三元一次方程组：{7x+2y-z=7,6x-y+z=7,4x+3y+z=9怎么解 x/2=y/3=z/5 x+3y-z/x-3y+z 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 x+y+z=4 2x+3y-z=6 3x+2y+2z=10 2x-y+2z=-17 3x+y-3z=-4 x+y+z=6