已知:8^x=9^y=6^z(x,y,z不=0),求证:2/x+3/y=6/z
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
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4x-3y-6z=0,x+2y-7z=0,且x、y、z都不为0,求(3x+2y+z)/(x+2y+3z)的值 快帮求
已知4x-3y-6z=0 ① ,x+2y-7z=0 ②,且x,y,z均不为0,求3x+2y+z÷x+2y+3z的值
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
已知方程组4x-y+3z=0 2x+y+6z=0且xyz不等于0,则x/y+y/z+z/x是多少
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
已知x^3+y^3-6x+2y+z+3+10=0,求(x-y+z)(x+y-z)的值.(z+3)是绝对值
如果|x+y+z-6|+|2x+3y-z-12|+|2x-y-z|=0求x,y,
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z均不为0,求3x*x+2y*y+5z*z/5x*x+y*y-
已知x,y,z满足方程组{x+y-z=6,y+z-x=2,z+x-y=0,求x,