化简下列式子-(7X-Y-2Z)-{[4X-(X-Y-Z)-3X+Z]-X}
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)
若实数x、y、z满足(x-z)2-4(x-y)(y-z)=0,则下列式子一定成立的是( )
如何化简(x+y+z)(x+y-z)(x-y+z)(-x+y+z)
①(x+y+z)(-x+y+z)(x-y+z)(x+y-z)
若实数x,y,z满足(x-z)²-4(x-y)(y-z)=0,则下列式子一定成立的是( )
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
(1)3x+4z=7;2x+3y+z=9;5x-9y+7z=8 (2)3x+4y+z=14;x+5y+2z=17;2x+
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.
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*
解下列方程组(1)3x-y+z=3 2x+y-3z=11 x+y+z=12(2)5x-4y+4z=13 2x+7y-3z
(1){x-y=2 z-x=3 y+z=-1 (2){x-y-z=2 3x+5y+7z=24 4x-y+2z=26