已知x/2=y/3=z/4,求下列各式 (1)(x+y+z)/x (2)(x-y+2x/(x-y-2z)
已知x/2=y/3=z/4,求下列各式 (1)(x+y+z)/x (2)(x-y+2x/(x-y-2z)
已知3X-4Y-Z=0,2X+Y-8Z=0,求下列各式的值:
已知x::y:z=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
已知x+y+z=0,x^2 + y^2 + z^2 = 1 ,试求下列各式的值:
已知2x+3y-4z=0,3x+4y+5z=0,求x+y+z/(除以)x-y+z的值.
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z都不为0,求(3x*x+y*y+4z*z)/(5x*x+y*
求下列各连比已知x:y=3:7,y:z=7:5,求x:y:z已知x:y=4:7,y:z=2:5,求x:y:z已知x:y=
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
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x*x+2y*y+5z*z/5x*x+y*y-
已知3x=4Y,5Y=6Z,求 (1)x:y:z;(2)x+y/y+z.
已知x/3=y/4=z/2,求x+2y-z/x+y+z=?
已知2x=3y=4z求2x-y+z分之x+y+z的值