20x+50y+z=16,x+y+z=100 请高手们给出尽量多的答案,小弟急用!

已知 x/(y+z)+y/(z+x)+z/(x+y)=1求 (x*x)/(y+z)+(y*y)/(x+z)+(z*z)/(x+y)=? (x+y-z)(x-y+z)= X+Y+Z=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 {x+y-z=11 y+z-x=5 z+x-y=1 {x+y-z=11,x-y-z=-5,x-y+z=1 X+Y+Z=20,4X+3Y-Z=14.3X+4Y-2Z=16 解三元一次方程组 x+y+z=50,1/4(x+z)=y,x=y+z 1.{x:y:z=3:4:5 2x+3y-5z=-142.{x-y-z=-1 3x+5y+7z=11 4x-y+2z=-13.{x+y=1 x+z=0 2x+y+2z=44.{x-y+z=-3 2x-y-z=-2 -3x+y+z=-15.{x-y+z=-3 3x+y-4z=6 2x+y-z=36.{x-2y+5z=16 2x+y-5z=7 2x-y+z=38 X/Y+Z=Y/X+Z+1=Z/X+Y-1=X+Y+Z,求x+y+z等于多少 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 已知实数x y z满足x/(x+1)=y/(y+2)=z/(z+3)=(x+y+z)/3,求x+y+z的值 x+y+z=6 x+2y+3z=14 y+1=z fangchengzu:X+Z=Y 7Z=X+Y+Z X+Y+Z=14 z+=x>y?++x: X+Y+Z=35 X/16+Y/10+Z/20=2.5 Z/16+Y/10+X/20=2.65怎么求x y z x:y=3:4 y:z=2:1 x+y+z=20 急!