解x+y=17、y+2-x=-1、z+x-y=3
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
解方程组:x-2y+z=-1,x+y+z=2,x+2y+3z=-1
(x+y-z)(x-y+z)=
x+2y=3 x+y+z=36 2x+y+z=15 2y=3z x-y=1 x+2y+z x-z=-1 2x+z-y=1
解方程组2x+y-3z=1,x-2y+z=6,3x-y+2z=9求x,y,z的值
x/2=y/3=z/5 x+3y-z/x-3y+z
已知 x,y,z都是正实数,且 x+y+z=xyz 证明 (y+x)/z+(y+z)/x+(z+x)/y≥2(1/x+1
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y
解三元一次方程组x:y=2:1,2x-y=3z,x+y+z=20
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=