5x-3y+12z=5 2x-y+3z=0 y+3z=6解方程组

解方程组：x+y+z=4,x+y+2z=5,3x+y-z=6 解方程组{3x+y-z=4,2x-y+3z=12,x+y+z=6} 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 已知方程组4x-5y+2z=0 x+2y=3z 则x:y:z 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 x-2y+3z=0,3x+2y+5z=12,2x-4y-z=-7.解方程组 解方程组:{3x+2y+2z=-1 4x-3y-5z=12 2x+6y+7z=-1 解方程组: (x+y)/3=(y+z)/4=(z+x)/5,3x-2y+6z+44=0 解方程组{2x+3y+z=11,x+y+z=0,3x-y+z=-2. 解三元一次方程组：x+y-z=0 ① 3x+y=6 ① 2x-y+3z=2 ② x+2y-z=5 ② x-4y-2z+6