{2x+3y+5z=285 2x+4y+7z=330 2x+5y+6z=345
2x+5y+4z=6,3x+y-7z=-4,x+y-z=?
已知2x+5y+4z=6 3x+y-7z=-4求x+y-z
5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z
x/2=y/3=z/5 x+3y-z/x-3y+z
若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10
{2x+3y-4z=-5 x+y+z=6 x-y+3z=10
2x+5y+4z=0,3x+y-7z=0,则x+y-z=?
解方程组:x+y+z=4,x+y+2z=5,3x+y-z=6
已知x/4=y/5=z/6 求x+y+z/3x-2y+z的值
已知x/4=y/5=z/6,求x+y+z/3x-2y+z的值.
{x+y+z=1;x+3y+7z=-1;z+5y+8z=-2
2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X