)2x+3y=5 3y-4z=3 4z+5x=7
1.已知x:y:z=4:5:7,求:(一)2x+3y+z/5z; (二)x+y/y+z 非常急,
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z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.
{5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=-
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