x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
(x+y-z)(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=-
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z.
X:Y:Z=3:4:5 X+Y+Z=36 二元一次方程 求出X Y Z
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
x/2=y/3=z/5 x+3y-z/x-3y+z
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.
X+Y+Z=?
已知 x,y,z都是正实数,且 x+y+z=xyz 证明 (y+x)/z+(y+z)/x+(z+x)/y≥2(1/x+1