3x+2y+z=13 (1) x+y+2z=7 (2) 2x+3y-z=12 (3)
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
1.x+y+z=21,x-y=1,2x+z-y=13.2.3x+2y+z=13,x+y+2z=7 ,2z+3y-z=12
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
3x+2y+z=13 x+y+2z=7 2x+3y-z=12 x=?y=?z=?
{3x+2y+z=13 x+y+2z=7 2x+3y-z=12,求x,y,z
x/2=y/3=z/5 x+3y-z/x-3y+z
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
解下列方程组(1)3x-y+z=3 2x+y-3z=11 x+y+z=12(2)5x-4y+4z=13 2x+7y-3z
3道高数题,1,函数F(x,y,z)=(e^x) * y * (z^2) ,其中z=z(x,y)是由x+y+z+xyz=
x+2y-z=1 3x-3y+z=2 3x+3y+z=7
已知{x:y:z=1:2:3,x+y+z=12,求x、y、z的值