Z=3Y/X+Y,求зZ/зX,зZ/зY

Z=3Y/X+Y,求зZ/зX,зZ/зY 已知(x+y)(x+z)=x,(y+z)(y+x)=2y,(z+x)(z+y)=3z,求x,y,z 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)=? (y+z)/x=(z+x)/y=(x+y)/z求x+y-z/x+y+z的值 x+y-z=3 y+z-x=5 z+x-y=7 求x,y,z x+2y=3x+2z=4y+z 求x:y:z x,y,z不是0.3z=4y,z=3x求（x+y）：（x+z）. x=y/z=z/3,x+y+z ＝12,求2x+3y+4z是多少, 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 若|x+3|+|y-2|+|2×z+1|=0求(x×z-y×z)(y-x+z)的值 若(x+y)/z=(y+z)/x=(x+z)/y 求（x+y-z)/(x+y+3z)的值 设函数z=z(x,y),由方程z=e^(2x-3z)+2y确定,求∂z/∂x,∂z/∂y (x+y-z)(x-y+z)= 求x.y.z. 求x、y、z 若z分之x+y+z=y分之x-y+z=x分之-x+y+z,求xyz分之(x+y)(y+z)(z+x) 已知 (x+y-z)/z=(x-y+z)/y=(y+z-x)/x,且xyz≠0,求代数式 ((x+y)(y+z)(x+z))/xyz