方程组2x-y+z=3 5x+2y+z=7 x+y-z=5 x=?y=?z=?
x/2=y/3=z/5 x+3y-z/x-3y+z
解方程组{z=x+y 3x-2y-2z=-5 2x+y-z=3
解方程组 z=x+y 2x-3y+2z=5 x+2y-z=3
解方程组2x+y-z=7 x+y+z =1 2x-y-z=5
解方程组:x+y+z=4,x+y+2z=5,3x+y-z=6
已知方程组4x-5y+2z=0 x+2y=3z 则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)
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
(x+y-z)(x-y+z)=
三元一次方程组2x+z=3 3x+y-z=8 x+3y+2z=3 5x+2y-3z=2 x+2y+z=6 7x-2y-4
解方程组:x+3y=5.y-2z=5.x+z=5
x:y:z=2:3:5解方程组 2x+3y-z=16