X-100=(Y+Z)×2／13 y-100=(x+z)×9／16 z-90=(x+y)×1／3

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)= x/2=y/3=z/5 x+3y-z/x-3y+z 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-2y+z)/9=(2x+y+3z)/10=-(3x+2y-4z)/3=1 连等,求x,y,z, 解方程组2x+y-3z=1,x-2y+z=6,3x-y+2z=9求x,y,z的值 X+Y+Z=? 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= 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 {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2 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 如果,根号x-3+| y-2 |+z^2=2z-1 求 （x+z)^y