已知x+2y+3z=54,3x+2y+2z=47,2x+y+z=31,那么代数式x+y+z的值是( ).
已知x+2y+3z=54,3x+2y+2z=47,2x+y+z=31,那么代数式x+y+z的值是( ).
已知x+2y+3z=54,3x+y+2z=47,2x+3y+z=31,那么代数式x+y+z的值是( )
已知x+2y+3z=54,3x+y+2z=47,2x+y+z=31,那么代数式x+y+z的值是
已知x=3y,z=7y(x≠0),求代数式2x+3y-z分之x+y+z的值
已知4X=7Y+5Z,2X+Y=Z,那么X:Y:Z的值是?
已知x=3y,z=7x(x不等于0),求代数式2x+3y-z分之x+y+z的值
4x-3y-6z=0,x+2y-7z=0是一个方程组,那么x-y+z/x+y+z的值等于
已知x^3+y^3-6x+2y+z+3+10=0,求(x-y+z)(x+y-z)的值.(z+3)是绝对值
已知x+2y+3z=54,3x+2y+2z=47,2x+y+z=31,求代数式x+y+z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.
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)