x-y=1 x+z=2 z-y=17x-y=1(1)x+z=2(2) z-y=17(3)

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)= 用行列式的性质证明：y+z z+x x+y x y z x+y y+z z+x =2 z x y z+x x+y y+z y z x 这个怎么证? (x-2y+z)(x+y-2z)分之（y-x)(z-x) + (x+y-2z)(y+z-2x)分之(z-y)(x-y) + (y+z-2z)(x-2y+z)分之（x-z)(y-z)=?第三部分那个是 （y+z-2x)(x-2y+z)分之（x-z)(y-z) 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求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^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)的值. x^2/(z+y)+y^2/(x+z)+z^2/(x+y)=0,求x/(z+y)+y/(x+z)+z/(x+y)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 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=? x/y=(x+z)/(y+z)y/z=(x+y)/(x+z) 方程组：{x+y-z=6,x+z=16,x-y+2z=17 x+y+z=6 x+2y+3z=14 y+1=z 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 x-y=1 x+z=2 z-y=17x-y=1(1)x+z=2(2) z-y=17(3) (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 (x+y-z)^2-(x-y+z)^2=?