{x+y-z=11 y+z-x=5 z+x-y=1

(x+y-z)(x-y+z)= X+Y+Z=? 已知x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求代数式x2/(y+z)+y2/(x+z)+z2/ 已知实数x,y,z满足x/(y+z)+y/(z+x)+z/(x+y)=1,求x2/(y+z)+y2/(z+x)+z2/( 解方程 .{x+y-z=11 {y+z-x=5 {z+x-y=1 怎样解三元一次方程组(1)x+y-z=11,y+z-x-5,z+x-y=1 f(x,y,z,w)=x*(x+y)*(x+y+z)*(x+y+z+w) x-y-z=-1 3x+5y+7z=11 4x-y+2z=-1 分别求出x=?y=?z=? x/2=y/3=z/5 x+3y-z/x-3y+z 已知 x/(y+z)+y/(z+x)+z/(x+y)=1 x+y+z=1 求xyz/(x+y)(y+z)(z+x)的最大值 {x+y+z=1;x+3y+7z=-1;z+5y+8z=-2