{x-2y+z=0 {3x+y-2z=0 {7x+6y+7z=100

4x-3y-6z=0,x+2y-7z=0是一个方程组,那么x-y+z/x+y+z的值等于 已知有理数x,y,z满足|x-z-2|+|3x-6y-7|+(3y+3z-40)^2=0,求x,y,z的值 已知有理数x、y、z满足条件|x-z-2|+(3x-6y-7)^2+|3y+3z-4|=0,求x、y、z 若4x-3y-6z=0,x+2y-7z=0,求代数式5x*5x+2y*2y-z*z/2x*2x-3y*3y-10z*10 如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y, 2x+5y+4z=0,3x+y-7z=0,则x+y-z=? 解三元一次方程：x+y-z=0,2x+y+z=7,x-3y+z=8 已知4x-3y-6y=0,x+2y-7z=0.求x-y+z\x+y+z的值 已知x+4y+3z=3x-2y-5z=0,求x+2y-z/2x-3y+7z的值 已知,方程组:4x-3y-7z=0 x+2y=10z 则(x-y+z)÷(x+y+z)=—— 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 已知x,y,z 大于0,x+y+z=2,求证 xz/y(y+z)+zy/x(x+y)+yx/z(z+x)大于等于2/3