1、2x+y+3z=38 2、3x+2y+4z=56 3、4x+y+5z=66
x+y+z=2 ① 2x+3y+z=38 ① x+y=3 3x-y-4z=5 ② 3x+4y+2z+56 ② y+z=5
x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
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=3:4:5,(1)求x+y分之z的值;(2)若x+y+z=6,求x,y,z.
x/2=y/3=z/5 x+3y-z/x-3y+z
x=y/z=z/3,x+y+z =12,求2x+3y+4z是多少,
1、2x+y+3z=38 2、3x+2y+4z=56 3、4x+y+5z=66
{5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=-
已知x:y:z=4:5:7,求:(1)2x+3y+z/5z; (2)x+y/y+z.
(4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai
x+y+z=2 4x+2y+z=4 2x+3y+z=1
已知x:y:z=3:4:5,3x+2y-4z=18.求:x+y+z.