解方程{①2x-y+z=6②-3x+2y-z=-9③x+y-2y=-1
解方程{①2x-y+z=6②-3x+2y-z=-9③x+y-2y=-1
解方程一;{x+y-z=6,x-3y+2z=1,3x+2y-z=-7.②{3x+4z=7,2x+3y+z=9,5x-9y
解方程:x+y+z=0 ① 4x+2y+z=3 ② 9x+3y+z=6 ③
解方程{3x -y+z=4 2x+3y-z=12 x+y+z=6
解方程组2x+y-3z=1,x-2y+z=6,3x-y+2z=9求x,y,z的值
3元1次方程x-2y=-9 3x-y+z=4{ y-z=3 { 2x+3y-z=122z+x=47 x+y+z=6
解方程x+y+2z=7① 2x+3y-z=12② 3x+2y+z=13③
解方程x-y+z=5,①2x+y-3z=15②,3x-2y+z=16③
试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y)
解关于w,x,y,z的方程w+8x+3y+5z=20①,4w+7x+2y+3z=-20②,6w+3x+8y+7z=20③
x:y:z=1:2:3 x+2y+3z=56解方程
x+2y+3z=28 x:y:z=1:2:3 解方程