紧急..x+y+z=20x+2y+1.5z=367x+10y+6z=100

(x+y-z)(x-y+z)= X+Y+Z=? 试证明(x+y-2z)+(y+z-2x)+(z+x-2y)=3(x+y-2z)(y+z-2x)(z+x-2y) 已知x、y、z满足方程组：x+y-z=6；y+z-x=2；z+x-y=0 求x、y、z的值 (x+y-z)^2-(x-y+z)^2=? x+y+z=4 2x+3y-z=6 3x+2y+2z=10 f(x,y,z,w)=x*(x+y)*(x+y+z)*(x+y+z+w) {2x+3y-4z=-5 x+y+z=6 x-y+3z=10 解方程组{x(x+y+z)=6,y(x+y+z)=12,z(x+y+z)=18 分解因式:f(x,y,z)=x^2(y-z)+y^2(z-x)+z^2(x-y) x,y,z为实数 且(y-z)^2+(x-y)^2+(z-x)^2=(y+z-2x)^2+(x+z-2y)^2+(x+y x,y,z为实数且(y-z)平方+(x-y)平方+(z-x)平方=(y+z-2x)平方+(z+x-2y)平方+(x+y-