3x-y+2z=3 2x+y-4z=11 7x+y-5z=1 用加减消元法,帮我计算
x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=?
快已知方程组;x+y-7z=0 3x-2y-z=0,且z≠0,求x:y:z加减消元法
帮我解方程组:3x-y+z=3,2x+y-3z=11,x+y+z=12.x=?y=?z=?
X +2y +3z =5 2X +3y +z =13 3X +y +2z =12 用加减消元法
急!用加减消元法做!要有详细过程! x+3y+z=-1,2x-y+3z=7,3x+y+2z=3
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
{5x-3y+z=2{5x+2y-4z=3{-5x+y-z=2 {x-y-z=-1{3x+5y+7z{4x-y+2x=-
x/2=y/3=z/5 x+3y-z/x-3y+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
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+2y+4z=17 2x+y+z=7 3x+y+2z=11