解方程组2x+y=5 ,2y+z=-3,2z+x=7
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
x:y:z=2:3:5解方程组 2x+3y-z=16
解方程组:x+3y=5.y-2z=5.x+z=5
解方程组:2x+3y+4z=20,x+y+z=7
X:Y=5:3,y:Z=7:5,2X—Y—Z=34.解方程组
解方程组{x:y=5:3,y:z=7:,5,2x-y-z=34
解方程组:x-2y+z=-1,x+y+z=2,x+2y+3z=-1
x+z=y 7*x=y+z+2 x+y+z=14 解这个方程组、
解方程组{2x+3y+z=11,x+y+z=0,3x-y+z=-2.