若3x+4y+5z=17,3x+2y+z=13,则x+y+z= )
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.
x/2=y/3=z/5 x+3y-z/x-3y+z
若{x+3y+10z=0 则 (x+y-z)/(x-y+z)
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
若x/3=y/2=z/5,则2x-3y-z/x-y+z=
若3x+7y+z=5,4x+10y+z=3,则x+y+z=?
若x/3=y/4=z/5,求x+y+z/3x-2y+z的值.
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
已知2x+5y+4z=15.7x+y+3z=14 则x+y+z=?
已知x+y=3,y+z=4,x+z=5,则x+y+z等于( )
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
2x+3y-4z=0.,3x+4y+5z=0,则x+y+z/x-y+z详细的解题过程