若齐次线性方程组{2x+y+z=0,ax-z=0,-x+3z=0}存在非零解,则系数a=——
当a,b取何值时,齐次线性方程组:{ax+y+z=0;x+by+z=0;x+2by+z=0有非零解
已知,方程组:4x-3y-7z=0 x+2y=10z 则(x-y+z)÷(x+y+z)=——
若{x+3y+10z=0 则 (x+y-z)/(x-y+z)
已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3
线性方程组2x-z=-1x+2y=0y+z=2即为2x+0×y-z=-1
x-3y+z=0,3x-2y-4z=0,则x:y:z=多少?
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
x+2y-4z=0 3x+y-z=0,则x:y:z=
x+2y-4z=0,3x+y-z=0,则x:y:z=?::
已知{x-3y+2z=0 3x-3y-4z+0,则x:y:z=?
已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z
已知x+2y-4z=0,3x-y-z=0,则3x+2y+z/x+2y+z=