(4y+3x-5z)(3x-4y-5z)急要步骤
已知x+y=3,y+z=4,x+z=5,则x+y+z等于( )
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*
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
已知3/x+y=4/x+y=5/y+z,求xyz/(x+y)(y+z)(z+x)的值
{x-z-y=0 x+y-3z=4 2x-5y+7z=21,不写步骤老师要说的,
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
已知3x=4Y,5Y=6Z,求 (1)x:y:z;(2)x+y/y+z.
(1){x-y=2 z-x=3 y+z=-1 (2){x-y-z=2 3x+5y+7z=24 4x-y+2z=26
(1)3x+4z=7;2x+3y+z=9;5x-9y+7z=8 (2)3x+4y+z=14;x+5y+2z=17;2x+
2) 4x-9z=17 3x+y+15z=18 x+2y+3z=2 (3) 2x+4y+3z=9 3x-2y+5z=11