x+y+z＝13,y-x＝2,100x+z+10y+x＝99

x+y−2z＝52x−y+z＝42x+y−3z＝10 x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 解一道三元一次方程x+y+z=13,y-2=z,100z+10y+x+99=100x+10z+y. (y-x)/(x+z-2y)(x+y-2z)+(z-y)(x-y)/(x+y-2z)(y+z-2x)+(x-z)(y-z x,y,z正整数 x>y>z证明 x^2x +y^2y+z^2z>x^(y+z)*y^(x+z)*z^(x+y) 2x+y+3z＝383x+2y+4z＝564x+y+5z＝66 x+2y+3z＝12x+3y+z＝23x+y+2z＝3 若x+2y-4z＝0 3x+y-z＝0 求x：y：z 化简(y-x)(z-x)/(x-2y+z)(x+y-2z)+（z-y)(x-y)/(x-2z+y)(y+z-2x)+(x 设x，y，z满足约束条件组x+y+z＝13y+z≥20≤x≤10≤y≤1，求u=2x+6y+4z的最大值和最小值（　　） (x-2y+z)(x+y-2z)分之（y-x)(z-x) + (x+y-2z)(y+z-2x)分之(z-y)(x-y) (x+y-z)(x-y+z)=