若 2x+5y+4z=6,3x+y-7z=-4,则x+y-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 若3x+7y+z=5,4x+10y+z=3,则x+y+z=? 2x+5y+4z=6,3x+y-7z=-4,x+y-z=? 若4x=7y+5z,2x+y=z,则x:y:z的值为 已知2x+5y+4z=6 3x+y-7z=-4求x+y-z 2x+5y+4z=0,3x+y-7z=0,则x+y-z=? 5x+3y+2z=2011 4x+6y+7z=2012 求x+y+z 已知x:：y：z=3：4：5,(1)求x+y分之z的值；（2）若x+y+z=6,求x,y,z. 已知2x+3y-4z=7 3x-2y+z=3 x+5y+9z=20 则 x+y+z= 若x :y :z=2 :3 :7 若x-2y+4z=1,x+3y-7z=0,则y:z=? 2X+Y+Z=10,X+2Y+Z=-6,X+Y+2Z=8 5X+4Y-3Y=13,2X-3Y+7Z=19,3X-Y=2X 3x+7y+z=5 ,4x+10y+z=6 ,x+y+z=